Trust
Every figure on this site was read somewhere. This is the list of somewheres, with the date we last opened each one to check it still says what we say it says.
Maintained by Pablo Ruiz Quintero · Last reviewed 2026-09-16
Each number in the code carries the identifier of its source, and this page is built from those identifiers. There is no hand-maintained list that can quietly fall behind the calculators — if a figure cites a document, that document appears here, and if we re-check a document, the date changes in both places at once.
Control joint spacing, panel proportions and cut depth for slabs on ground.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
2008 edition, current
The exact definitions behind every unit conversion on this site: the inch as 25.4 mm exactly, and the foot, yard and acre that follow from it.
Checked 2026-09-16 · Open the document
The definition of aggregate bulk density, and the reason this site publishes it as a range rather than a single figure.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
The requirement that anything carrying a load be founded below the frost line, which is what sets fence post depth in cold climates.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Minimum roof slope for asphalt shingles, underlayment requirements, and the fastening rules behind the nail counts.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Standard cycle ratings for torsion springs, the definition of a cycle, and how door R-value is measured — which is not the same thing manufacturers advertise.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
31st edition
The torsion spring rate formula — k = E·d⁴ ÷ (10.8·D·N) in inch-pounds per turn — and the relationship between wire diameter, coil count and fatigue life. It is the arithmetic behind every spring on a garage door and it is nowhere on a price page.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
What counts as adequate preparation before a coating goes on concrete, and the profile a floor coating needs. It is the standard behind the single fact that decides whether an epoxy floor lasts: acid etching does not produce it and grinding does.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
The two tests that measure whether a slab is dry enough to coat — calcium chloride vapour emission and in-situ relative humidity. They are the reason an epoxy floor peels, and almost nobody runs them before quoting.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
8th edition
The method a real heating and cooling load calculation follows, and the internal gain figures for occupants and kitchens. It is the standard this page estimates towards and openly does not replace.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
SEER2 / HSPF2, effective January 2023
The legal minimum efficiency a new split system may have, which differs by region: the South and Southwest require more than the North. It is why the cheapest unit available to you depends on where you live.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
How far above the calculated load equipment may be sized — the rule that makes oversizing a defect rather than a safety margin.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
The climate zone each state falls in, which sets the heating and cooling load per square foot.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Substrate flatness tolerances by tile size, movement joint spacing, and the assemblies required in wet areas.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Mortar coverage requirements — 80% contact on a dry floor and 95% in a wet area or exterior — and the trowel sizing that follows from them.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Base depth by use, the one-inch bedding layer, edge restraint, and the requirement that the base be compacted in lifts.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Buried course depth, base thickness, drainage aggregate behind the wall, and the height above which an engineered design is required.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
The five levels of drywall finish, what each one includes, and which level suits which final decoration.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Fastener spacing, maximum framing spacing for each board thickness, and the requirement for 5/8 in board on ceilings framed at 24 in.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Stud spacing and size for load-bearing and non-load-bearing walls.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
The method for sizing gutters and downspouts from roof area and rainfall intensity, and the slope a gutter run needs.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Fastening, the expansion allowance vinyl siding must be hung with, and where starter strip, J-channel and corner posts go.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Seam placement rules, the requirement to power stretch rather than knee-kick, pad specification and pile direction.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Expansion gap, acclimation, subfloor flatness tolerance and moisture limits for wood flooring; and for refinishing, the depth a sanding pass removes, the usable thickness above the tongue, and the grit sequence a floor has to go through before it takes finish.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
based on the 2018 IRC
Joist spans by size, species and spacing; beam spans by post spacing; the maximum joist overhang; ledger fastening; and the footing sizes that follow from the tributary area each post carries.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
That a deck is a structure with its own span and connection requirements, the ledger attachment rules, and the guard requirement above 30 inches of drop.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Maximum riser height, minimum tread depth, the 3/8 inch limit on variation between risers, guard height, and the four-inch sphere rule that sets baluster spacing.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Compacted density of hot mix asphalt, the spread rate in pounds per square yard per inch, minimum and maximum lift thickness against the nominal aggregate size, and the temperature below which a mix can no longer be compacted.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Layer thicknesses for residential driveways, the aggregate base depth beneath them, when an overlay is appropriate rather than a reconstruction, and the interval at which sealcoating is actually useful.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
How many BTU per hour a gas line of a given diameter carries at a given length, which is what decides whether an existing half-inch branch can feed a tankless unit or whether the line has to be replaced back to the meter.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Minimum roof slope for exposed-fastener and standing seam panels, panel coverage widths, fastener spacing and pattern, and the panel length above which thermal movement has to be allowed for with floating clips.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Dimensional change coefficients by species — how much a board moves across its width for each 1 % change in moisture content — and the equilibrium moisture content of wood at a given indoor relative humidity.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Commercial stair geometry: the 7 inch maximum riser and 11 inch minimum tread that apply where the residential code does not, and the minimum width for an occupied means of egress.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
The actual dressed dimensions behind every nominal softwood size — why a 2 × 4 measures 1 1/2 by 3 1/2 — and the surfaced thicknesses for boards one inch nominal and under.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
How hardwood is sold: thickness in quarters of an inch of the rough board, surface measure taken on the actual width, and the difference between rough and surfaced thickness that decides what you can get out of a board.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
The three formulas that turn a log's small-end diameter and length into board feet, the half-inch-per-four-feet taper allowance the International rule applies, and the known bias of the Doyle rule against small logs.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
The distinction between terminal and line posts and the pipe sizes each takes, maximum line-post spacing, fabric gauges and mesh sizes, and the schedule of tension bars, tension bands, brace bands and ties that fixes the fabric to the frame.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Whole-window U-factor for single glazing, older clear double glazing and current low-E double and triple glazing, and the solar heat gain coefficient that decides whether a window helps or hurts in a cooling climate.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
The maximum U-factor and the solar heat gain coefficient a window has to meet in each climate zone to qualify, and the heating degree days used to work out what a change in U-factor is worth in a year.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
The R-value recommended for attics, walls and floors in each climate zone, and the heating degree days behind those recommendations.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Foot-candles recommended for each kind of room and for task areas within them, which is what turns a room's size into a number of fixtures instead of a guess.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
The 80 per cent continuous-load limit that decides how many fixtures a 15 or 20 amp circuit carries, and the clearance a non-IC rated housing needs from insulation.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
2024 reference year, released 19 February 2026
The state labour index applied to the labour half of every estimate. Never to the material half.
Checked 2026-09-15 · Open the document · 1 entry in the changelog
First hour rating as the sizing metric for storage tanks, peak-hour demand by fixture, and the flow rate and temperature rise method for tankless units.
Checked 2026-09-16 · Open the document
The share of household water that goes on landscape irrigation, and the proportion of it that is wasted through overwatering and runoff — the figures behind the running-cost comparison between a living lawn and an artificial one.
Checked 2026-09-16 · Open the document
Yield per bag for the 80, 60 and 40 lb bags, in cubic feet of set concrete.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
Yield per bag for the 50 lb bag.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
Published spread rate per gallon, recommended film thickness and the number of coats each product is rated for.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Plank widths, the exposure each is installed at, and the coverage per plank that follows.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Bundle coverage and bundles per square for architectural shingles, and the coverage of hip and ridge cap.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Joist spacing for composite decking — 16 inches on centre laid perpendicular, 12 inches laid diagonally, 12 inches for stair treads — and the gapping the boards need at the ends and sides.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Roll width and the direction of the pile, compacted base depth, infill weight per square foot, staple and seam-tape spacing, and the service life the warranties are written against.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Rated input and output in BTU per hour for gas units and kilowatts for electric ones, the temperature rise each published flow rate is measured at, minimum activation flow, and the gas supply and electrical service each model requires.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Indoor head capacities offered, the port count and rated capacity of multi-zone outdoor units, the connected-capacity ratio a multi-zone condenser permits, and the maximum line-set length and vertical lift between the outdoor unit and each head.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
R-value per inch for blown fibreglass, blown cellulose, batts, mineral wool and both foams, the settled depth each R-value needs, and the square feet a bag covers at that depth.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
These are ours. Nobody publishes a free, authoritative national price for a bag of concrete mix, so where a figure is our own compilation we say so and show the method rather than dressing it up as a citation.
Pounds per cubic yard, low to high, for crushed stone, base rock, pea gravel, river rock, sand, decomposed granite and topsoil.
How we arrived at it — Published loose weights from quarries and landscape suppliers across several regions, expressed as the range they actually span. Density moves with gradation, stone type and — most of all — moisture: the same yard of sand can weigh 2,600 lb dry and over 3,000 lb after rain. Anyone quoting one number for this is hiding a spread you will pay for, so we quote both ends and let the tonnage come out as a range too.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
Price per ton, low to high, by aggregate type, and the typical delivery minimum and haul charge.
How we arrived at it — Quarry and landscape supply pricing for material delivered to a residential address, compiled nationally. Aggregate is the most freight-sensitive material on this site — the stone is cheap and the truck is not — so the distance to the pit moves this figure more than the state does.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
Recommended depths by use, the compaction allowance by material, and the carrying capacity of a pickup and a dump truck.
How we arrived at it — Depths follow common residential practice and the guidance published by paver and segmental wall manufacturers for their own bases; compaction allowances are the volume a material loses between the loose pile and the compacted layer, which is why ordering the compacted depth leaves you short. Where a figure is a trade rule of thumb rather than a specification, the page says so.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
Design frost depth by state, post spacing, the one-third burial rule, and concrete per post hole.
How we arrived at it — Frost depths are the design figures local jurisdictions adopt, compiled by state and given as the deeper end where a state spans a range — running a post short is not a mistake you can correct later. They are a starting point and not a substitute for your building department, which is the only body whose number counts.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Material price per linear foot by fence type, installed labour, gate hardware and removal of an existing fence.
How we arrived at it — Material and labour kept apart, because fencing is one of the trades where doing it yourself saves the larger half. Gates are priced separately per unit rather than folded into the per-foot figure: they need heavier posts, hardware and adjustment, and they are where a fence quote and a fence estimate usually diverge.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Incoming cold water temperature by climate zone, fixture flow rates, and daily hot water use by household size.
How we arrived at it — Incoming water temperature is the figure that decides whether a tankless unit works, and it is almost never published next to the units being sold. These are seasonal-low values by climate zone — the winter case, because that is when a tankless unit disappoints. Fixture flows assume current low-flow fittings; older fixtures use considerably more.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Installed price by heater type and capacity, the common installation extras, and the annual energy cost by fuel and efficiency.
How we arrived at it — Installed pricing includes the unit, the fitting and disposal of the old one. The extras are listed separately because they are what makes a tankless quote differ from a tank quote by thousands: a larger gas line, new venting, a condensate drain or an electrical panel upgrade. Running cost is computed from daily use, temperature rise and the unit's efficiency rating at national average energy prices.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Material prices per gallon for one-part epoxy paint, water-based and 100 per cent solids epoxy, polyaspartic, flake and clear topcoat, plus preparation and application labour by the square foot.
How we arrived at it — Material is priced per gallon and converted to the job by computed coverage rather than by the figure on the tin. Preparation is priced separately from application because it is the line that decides whether the floor lasts three years or fifteen, and it is the line a cheap quote drops.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
Installed prices for sectional doors by construction and size, torsion spring sets by cycle rating, and openers by drive type and horsepower.
How we arrived at it — Doors are priced by size and construction rather than as a single range, because a 16 ft insulated door and an 8 ft single-skin one are both sold as 'a garage door'. Springs are priced by cycle rating, which is the variable that decides how often you buy them again.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
Volume solids, recommended film thickness and installed prices for garage floor coating systems, from one-part epoxy paint to polyaspartic.
How we arrived at it — Coverage is computed rather than quoted: 1,604 ft² per gallon at one mil of dry film at 100 per cent volume solids, divided by the film thickness the maker specifies. Published coverage figures are collected only as a check on that arithmetic, because they are routinely quoted at a film thickness the maker does not recommend.
Checked 2026-09-18 · No stable public link — cited the way it is cited on paper, by publisher and title
How much the published spread rate drops on each substrate and texture, when primer is genuinely needed, and the coverage of garage floor epoxy kits.
How we arrived at it — Manufacturers publish spread rate for a smooth, sealed, previously painted surface — the best case. The adjustments here are how far short of it each real substrate falls: new drywall drinks the first coat, knockdown texture adds surface area you cannot see, and bare wood takes two coats before it stops absorbing. Every one is applied to the first coat only, because that is where the difference lives.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Paint and primer price per gallon by grade, sundries, professional labour per square foot, and installed epoxy floor coating cost.
How we arrived at it — Material and labour apart, as everywhere on this site. Painting is the trade with the widest gap between the two: the paint for a room is a small fraction of what a crew charges to put it on, which is why it is also the job most often done by the homeowner.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Thinset coverage by trowel notch, the trowel each tile size needs, and grout coverage from tile dimensions and joint width.
How we arrived at it — Thinset coverage is published per trowel notch, not per tile — and the notch is set by the tile size, which is the step everyone skips. A quarter-inch notch covers more than twice what a half-inch one does, so quoting a bag count from square footage alone is wrong by a factor of two at the extremes. Grout follows a dimensional formula rather than a rule of thumb, because it depends on tile size, thickness and joint width together.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Tile price per square foot by type, thinset, grout, backer board and waterproofing, and installed labour by surface.
How we arrived at it — Labour is quoted separately for floors, walls and showers because they are not the same job — a shower is several days of waterproofing and small cuts, and pricing it per square foot at floor rates is how tiling quotes end up being argued about.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Pavers per square foot by size, waste by laying pattern, wall block coverage per course, and joint sand coverage.
How we arrived at it — Waste here is driven by cuts at the perimeter, and the pattern decides how many of them are diagonal. A running bond cuts one end of each perimeter unit; a 45-degree herringbone cuts both ends of nearly every one, on the bias, and a bias offcut fits nowhere.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Paver and wall block prices, bedding and joint sand, edge restraint, and installed labour including excavation and base preparation.
How we arrived at it — Labour here includes the excavation and the base, which together are most of the job and all of the risk. Pricing pavers by the square foot of finished surface hides the fact that a driveway needs twice the base a patio does, and that the difference is dug out by hand or by machine depending on access.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Board sizes stocked, joint compound consumed per sheet at each level of finish, tape and screw counts.
How we arrived at it — Compound is the figure nobody publishes usefully, because it depends entirely on the level of finish being worked to — a Level 3 wall behind tile uses a fraction of what a Level 5 wall under a gloss paint does. These figures are per sheet at each level, which is how an estimator actually works it out.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Board price by size and thickness, compound and tape, and installed labour split into hanging and finishing.
How we arrived at it — Hanging and finishing are separate trades and separate prices, and the split matters: hanging is fast and cheap, finishing is slow and is where the level of finish shows up on the invoice. Quotes that give one number per square foot are averaging over a decision the customer has not been asked to make.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
The peak short-duration rainfall rate each state's gutters have to cope with.
How we arrived at it — Design intensity is the short-duration peak a drainage system is sized against, not the annual average — a gutter fails in the ten minutes of a summer downpour, not over a wet year. Values are compiled by state at the higher end where a state spans a range, because undersized gutters overshoot at the eave and put water against the foundation, which is the expensive failure.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Installed price per linear foot by gutter material and size, downspout and accessory prices, and removal of existing gutters.
How we arrived at it — Seamless aluminium is priced installed because it is rolled on site from a coil and cannot sensibly be bought as material alone. Sectional vinyl and steel are priced as material plus labour, since they can be. The gap between the two is why almost every professional gutter job in the US is seamless.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Box coverage for vinyl, accessory lengths for J-channel, corner posts and starter strip, soffit coverage, and waste by wall complexity.
How we arrived at it — Vinyl is sold by the box and almost every box is two squares, but the accessories are where a siding order goes wrong: J-channel, corners and starter are linear items that no per-square figure captures, and they are what a supplier's list leaves off when a homeowner phones with a square footage.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Material price per square by siding type, installed labour, house wrap, and removal and disposal of existing siding.
How we arrived at it — Material and labour separately, and removal separately again. Tearing off old siding varies more than anything else in the quote — vinyl comes off in an afternoon, and anything nailed through into sheathing does not.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Standard roll widths, pad thickness and density by traffic, the carpet a stair tread consumes, and the waste a room's proportions force.
How we arrived at it — Carpet is made in fixed widths — overwhelmingly 12 ft, sometimes 15 — and that single fact drives the waste on a job more than anything the installer does. The figures here are the widths actually stocked, not the ones theoretically available, because a roll you cannot buy locally is not an option.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Carpet price per square foot by grade, pad, installation labour, stair charges and removal of the old carpet.
How we arrived at it — Retail carpet is quoted per square foot or per square yard and installed labour is quoted separately, per square foot and per stair. Stairs are priced per step rather than by area everywhere in the trade, because a stair takes several times longer per square foot than a flat floor.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Roll coverage for synthetic and felt underlayment, starter strip, drip edge lengths and nails per square.
How we arrived at it — Published coverage from the packaging of the products a homeowner actually finds at a supply house and a big-box store. Where two manufacturers disagree, the figure here is the more conservative of the two — running short on underlayment mid-roof is a different kind of problem from running short on stone.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Waste allowance by roof shape, the weight of a square of stripped shingles, and how that weight maps to skip and dumpster sizes.
How we arrived at it — Waste follows trade practice: a plain gable wastes far less than a roof full of hips and valleys, because every valley is a cut and every cut is scrap. Tear-off weights are derived from published bundle weights — three bundles to the square — which is why a second layer roughly doubles the figure and why disposal is priced by weight, not by area.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Material price per square, installed labour per square, tear-off labour and disposal cost.
How we arrived at it — Contractor and supply-house pricing for a standard architectural shingle roof, compiled nationally and split into material, labour, tear-off and disposal so each can be checked separately. Only the labour half is adjusted by region — the shingles cost much the same everywhere, the crew does not.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
The heating and cooling load per square foot used to size equipment on this page, by climate zone, and the adjustments for insulation, glazing, sun and ceiling height.
How we arrived at it — These are screening figures, compiled from trade sizing practice by climate zone, and they are deliberately published as ranges. They are NOT a Manual J: a real load calculation works room by room from the actual construction, orientation, window specification and infiltration rate, and it routinely lands 20-30% away from any per-square-foot rule. Use these to sanity-check a quote or size a budget, and get a Manual J before buying equipment.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Installed price ranges for central air conditioning, heat pumps, gas furnaces and mini-splits, by capacity.
How we arrived at it — Installed pricing including equipment, refrigerant lines and commissioning, compiled nationally. Ductwork is excluded and stated separately, because replacing a system in existing ducts and installing one where none exists are different jobs with a factor of two between them.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Square feet per carton for laminate, vinyl plank, engineered and solid wood flooring, and the coverage of underlayment rolls.
How we arrived at it — Carton coverage read off the products stocked by US big-box stores and flooring suppliers. It varies more than any other figure on this site — two laminates on the same aisle can differ by a third — so the calculator takes the number from your own box when you give it one, and the default is only a starting point.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Material price per square foot by floor type, installed labour, removal of the old floor, and the cost of sanding and refinishing existing wood.
How we arrived at it — Retail and supplier pricing for material, and contractor pricing for labour, kept apart so each can be checked on its own. Refinishing is priced as its own job — sanding, stain and finish coats — because for a solid wood floor it is the real alternative to replacement, and nobody publishes the two side by side.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Waste allowance by room layout and lay direction, transition strip counts, and trim quantities.
How we arrived at it — Waste here is driven by cuts that cannot be reused. An open room wastes the end of each row; a house full of doorways starts a new row at every one; a diagonal or herringbone layout cuts both ends of nearly every plank on the bias. Manufacturers publish 5% and installers order 10%, and the gap between those two numbers is the reason this allowance is editable.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Low, typical and high price per bag, by bag weight.
How we arrived at it — National big-box retail shelf prices for the same mix, read across several metros and reduced to a low–typical–high range. It is a shelf price, not a contractor price: a trade account beats it.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title
Price per cubic yard of delivered ready-mix concrete.
How we arrived at it — Trade and supplier pricing for a standard residential mix, delivered, compiled into a national range. Plant-to-site distance moves this figure more than geography does, which is why it carries a freight sensitivity rather than a regional multiplier.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
The four-to-five yard minimum load and the charge per yard below it.
How we arrived at it — Published minimum load schedules from US ready-mix plants. Plants differ, and a few waive the fee off-peak — the figure here is the common case, and it is shown as a separate line so you can strike it out if your plant does not charge it.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title · 1 entry in the changelog
Crew hours per square foot and the national loaded hourly rate for placing and finishing concrete.
How we arrived at it — A loaded rate — wage plus burden plus the contractor's margin — not a wage. It is the number that appears on an invoice, which is what a homeowner is comparing against.
Checked 2026-09-15 · No stable public link — cited the way it is cited on paper, by publisher and title
The board lengths each decking material is actually stocked in, screws and hidden clips per square foot, and the maintenance cycle a wood deck needs against a composite one.
How we arrived at it — Board lengths are what the big-box and lumberyard shelves actually carry, not what a mill will cut to order. That matters because the waste on a deck is not a percentage: it is whatever falls off the end of a stock board, and it depends on how the deck width divides into the lengths available. Fastener counts assume two per board at every joist crossing, which is what the code and every manufacturer require.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Price per linear foot for pressure treated, cedar, composite and PVC decking; framing lumber, joist hangers and footings; railing by the foot; and installed labour for deck, stairs and railing.
How we arrived at it — Decking is priced by the linear foot of board rather than by the square foot of deck, because that is how it is sold and because the two diverge as soon as the board width changes. Framing and decking are kept apart in the result: on a pressure treated deck the frame is usually the larger half of the lumber bill, and on a composite deck it is not.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Seeding rates by species for a new lawn and for overseeding, weekly water requirement, growing season length by region, mowing frequency, and annual nitrogen per thousand square feet.
How we arrived at it — Compiled from the turfgrass guidance published by cooperative extension programmes in the states where each species is actually grown, taking the middle of each published range. Seeding rates are the single most variable figure in lawn care — a tall fescue wants four times the seed a bermuda does — so they are given per species rather than as one number, and doubled nowhere: the rate for a new lawn and the rate for overseeding an existing one are listed separately because they are not the same job.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Price per square foot of sod by species, pallet coverage and piece size, grass seed by the pound, starter fertiliser, screened topsoil, and installed labour for laying sod and for preparing ground.
How we arrived at it — Sod is priced per square foot but bought by the pallet, so both are given: a pallet covers between 400 and 500 square feet depending on the farm and the region, and the rounding up to whole pallets is shown rather than hidden. Delivery is a large share of the cost of sod and is quoted separately, because it is charged per load and not per square foot.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Turf price per square foot by pile quality, infill, weed barrier, seam tape and fasteners, the excavation and base course under it, and installed labour.
How we arrived at it — Quoted as material and installation kept apart, because artificial turf is sold almost entirely as an installed price by companies that do not publish the split. The base underneath is the part that decides whether the surface stays flat, it is the same compacted aggregate a patio needs, and it is priced here from the same aggregate survey the gravel calculator uses rather than as part of an opaque per-foot figure.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Square feet a ton covers at each compacted depth, the density of recycled asphalt millings against hot mix, sealcoat spread rate per coat, and the plant minimum loads that make a small job disproportionately expensive.
How we arrived at it — Coverage is derived from compacted density rather than quoted as a rule of thumb, so it moves correctly with depth: the figures here are the arithmetic, and the arithmetic is shown. Millings are given as a range rather than a single density because what is in them depends entirely on the road they came off, and a supplier who cannot tell you the difference is selling you an unknown.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Delivered price per ton of hot mix and of millings, installed price per square foot for a new driveway and for an overlay, crack filling and patching by the unit, sealcoating by the square foot, and removal of an existing surface.
How we arrived at it — Paving is quoted per square foot installed almost everywhere, which hides the two things that actually move the price: the tonnage, which is a function of depth, and the mobilisation, which is a function of nothing but the size of the job. Both are broken out here. Hot mix cannot be bought in small quantities in any useful form — it has to arrive hot and be laid immediately — so the plant minimum is priced as the real constraint it is rather than ignored.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Recommended depth by mulch type, how much depth an organic mulch loses to decomposition in a year, the clearance a trunk needs, and the depth beyond which mulch starts to do harm rather than good.
How we arrived at it — Depths come from the extension guidance of university horticulture programmes, taken at the middle of each published range. The decomposition figure is the one that matters for ordering and is almost never given: an organic mulch loses roughly an inch a year, which is why mulching is an annual top-up of an inch or two rather than a fresh three inches every spring — and why calculators that ask for the finished depth and ignore what is already down over-order by half.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Price per bag and per bulk cubic yard by material, bags to a pallet, delivery charges for bulk loads, weight per cubic yard wet and dry, and installed labour for spreading.
How we arrived at it — Both packagings are priced because the choice between them is the real decision and it turns on volume: bagged mulch costs roughly half as much again per cubic yard as bulk, but bulk carries a delivery charge that is the same whether you order two yards or ten. The crossover is arithmetic and it is published here rather than left to the yard. Weight is given wet and dry because a cubic yard of soaked hardwood weighs close to twice what the same yard weighs dry, and that decides whether it fits in a pickup.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Panel price per square foot of coverage by profile and gauge, trim and flashing by the ten-foot length, fasteners and closures, and installed labour for exposed-fastener against standing seam.
How we arrived at it — Panels are priced per square foot of COVERED width rather than of material, because that is how they are sold and because coverage and overall width are not the same number — a 36 in corrugated sheet covers 34 in once it is lapped. Trim is priced by the piece in ten-foot lengths, since that is the unit that gets delivered and the unit that gets wasted: a 42 ft ridge needs five pieces, not 4.2.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Board price per square foot by species, installed labour by method — nail, staple, glue and float — cleats and staples by the box, flooring adhesive by the pail, underlayment paper, and subfloor preparation.
How we arrived at it — Labour is collected by METHOD rather than by material, because the method is what the floor fitter actually prices: gluing a floor to a slab costs roughly half again what nailing the same boards to plywood costs, and the boards are identical. Fasteners are priced by the box of 1,000 since that is the unit sold, and adhesive by the 4-gallon pail with its trowel-notch spread rate, which is the only figure that turns square feet into pails.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
Equipment price for single-zone kits and for multi-zone outdoor units by port count, indoor heads by style, line set by the foot, line-hide cover, condensate pumps, mounting, the dedicated circuit each outdoor unit needs, and installation labour split between the system and each head.
How we arrived at it — Labour is collected as a base for the outdoor unit plus a figure for each indoor head, which is how ductless work is actually quoted and the reason a four-zone system does not cost four times a one-zone system. Equipment is separated from labour throughout, because the same kit bought online and fitted by a contractor and the same kit supplied by that contractor differ by the markup, not by the work.
Checked 2026-09-16 · No stable public link — cited the way it is cited on paper, by publisher and title
The comfort rules carpenters lay out to — 2R + T, R + T and R × T — the thickness a stringer is dropped by at the bottom, nosing projection, tread and riser stock by the piece, and installed labour per step for interior and exterior stairs.
How we arrived at it — Riser counts are presented as a short list of the integers around the ideal rather than as one answer, because the total rise is fixed and the riser count is the only free variable: the comfortable stair and the stair that fits the available run are frequently different integers, and every calculator that returns a single number hides that choice.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Density by species at service moisture content, the much higher weight of freshly treated southern pine, and price per board foot for hardwood against price per piece for dimensional softwood.
How we arrived at it — Weight is computed from ACTUAL dressed dimensions and density, never from nominal ones, because nominal size is a billing convention and a truck axle does not care about billing conventions. Treated softwood is listed wet, which is how it leaves the yard and how it is carried.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Fabric by the roll and by the foot at each height and gauge, line and terminal posts by the piece, top rail in 21 ft lengths with its sleeves, bands, bars, caps and ties, gates by leaf width, and installed labour per linear foot.
How we arrived at it — Priced component by component rather than per linear foot, because chain link is the one fence where the per-foot figure hides the job: the terminal posts, bands and bars cluster at corners, ends and gates, so two fences of identical length and different shape carry genuinely different bills. A per-foot quote is an average over a shape the quoter has already seen and the buyer has not described.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Installed price by united inches and frame material, the difference between an insert and a full-frame replacement, capping and trim, disposal, and the labour each method takes.
How we arrived at it — Priced by UNITED INCHES — width plus height — because that is how the window trade actually quotes, and because a price per window is meaningless across a house where a bathroom unit and a picture window differ by a factor of four. The insert and full-frame figures are collected separately rather than averaged, since it is the single distinction that most often explains why two quotes for the same house disagree.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Material by the bag and by the square foot at a given R-value, installed labour by method, air sealing by the square foot of attic floor, and the cost of removing contaminated existing insulation.
How we arrived at it — Priced at a target R-value rather than by the bag, because a bag of loose fill covers a completely different area at R-30 than at R-60 and comparing bag prices across products is meaningless. Air sealing is listed separately rather than folded in, since it is a different trade and — on the numbers — a better buy than the insulation it goes under.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title
Housings and trims by diameter and type, LED retrofit modules, installed labour separated for open ceilings and for cutting into finished ones, a new circuit, and dimmers.
How we arrived at it — Labour is collected separately for new construction and for remodel work, because cutting a hole in a finished ceiling, fishing cable through it and patching afterwards is a different job from clipping a housing to a joist before the drywall goes up — and it is roughly double. Every published figure for this work averages the two.
Checked 2026-09-17 · No stable public link — cited the way it is cited on paper, by publisher and title