Carpet
Carpet installation cost
Carpet runs about $7.45 a square foot installed with the old carpet taken out — but it comes off a roll twelve feet wide, so what you actually pay for is linear feet, not floor area. This works out both, and the waste the roll forces on your rooms.
Written and edited by Pablo Ruiz Quintero
Last reviewed 2026-09-16 · Nothing you type leaves your browser
What are you carpeting?
Twelve feet is what nearly everything comes in. Fifteen exists in some ranges and can transform the waste on a wide room.
Room 1
12' 6", 12.5 and 12-6 all work
Each room is laid out on its own, because each one fits the roll differently.
Counted per step, which is how the trade prices them.
Three feet is standard for a residential flight.
Denser pile and a better backing. The sensible choice for a bedroom, and the point at which the pad starts mattering more than the carpet.
The usual residential pad. Adequate under a mid-range carpet in a bedroom.
One transition strip each.
Used only to pick a regional labour rate. It stays in your browser.
Carpet to buy
312 ft²
260 ft² of floor · 26 linear ft of 12 ft roll · 20% waste · 1 seam
The waste is the room, not the installer
Carpet comes in fixed widths, so what you pay for is linear feet off a 12 ft roll — not the floor area. How well your room divides into that width decides the waste before anybody picks up a knife.
How each room fits the roll
Both orientations tried; the cheaper one chosen.
- Living room312 ft²
Roll runs along the width · 26 linear ft · 1 seam · 20% waste — the other way round would waste 85%, or 168 ft² more
Shopping list
- Carpet, mid range
26 linear ft off a 12 ft roll — 312 ft² of material for 260 ft² of floor312 ft² - Pad — Standard — 7/16 in, 6 lb
Cut to fit, so the roll width does not apply260 ft² - Tack strip
Around 66 ft of perimeter, in 4 ft lengths17 pieces - Transition strips
One per doorway or change of floor2 strips - Waste from the roll width
Not the installer's doing — it is how the room fits the roll52 ft² · 20%
What it costs
National average. Carpet, pad, supplies and installation, plus taking the old carpet out and disposing of it.
$7.45 per square foot of floor. Carpet is $1,123 of it, pad $143, and labour $351.
Worth knowing
- In living room the roll runs along the width, which wastes 20% instead of 85% — a saving of 168 ft² of carpet. Tell the installer which way you priced it, because they will not know you cared.
- This layout needs 1 seam. Seams should run with the light rather than across a window, and never through a doorway or a traffic lane — a seam in the wrong place is visible for the life of the carpet.
- Carpet has to be power stretched into place, not knee-kicked. An unstretched carpet ripples within a year or two, and the fix is to lift it and do the job properly — which is why the installer matters more here than the carpet grade.
On this page — 10 sections
- 01Reading the result
- 02Why carpet wastes so much, and whose fault it is not
- 03The direction decision, and how to win it
- 04Stairs, which are priced per step for a reason
- 05The pad matters more than people think
- 06What separates a good installation from a cheap one
- 07What carpet installation costs per square foot, and where the money goes
- 08Five ways this goes wrong
- 09How the calculator works it out
- 10The words on a carpet quote
Reading the result
The short version
- Carpet is sold in fixed widths — nearly always 12 ft. You buy linear feet off a roll, not square feet of floor.
- The waste is decided by the room, not the installer. A 13 ft room needs a second strip, and that strip is a full 12 ft wide.
- Which way the roll runs changes everything. A 20 × 13 ft room wastes 20% one way and 85% the other.
- Stairs are priced per step, everywhere in the trade, because they take several times longer per square foot than flat floor.
The headline is the carpet you have to buy, which is not the same as the floor you are covering. The panel underneath lays out each room against the roll separately, tries both orientations, picks the cheaper one and tells you what the other would have cost.
That comparison is the reason this page exists. It is the single biggest lever on a carpet order, it is invisible on every other calculator in this market, and it is decided before anyone picks up a knife.
linear ft = ceil( room width ÷ roll width ) × room length
- roll width
- 12 ft almost always, 15 in some ranges
- ceil
- you cannot buy part of a strip
- × roll width
- gives the square feet you actually pay for
Worked through — A 20 × 13 ft room on a 12 ft roll: running along the 20 ft length needs 2 strips × 20 = 40 linear ft, or 480 ft². Running across needs 2 strips × 13 = 26 linear ft, or 312 ft². Same floor, same roll, 168 ft² apart.
Why carpet wastes so much, and whose fault it is not
Every other flooring material on this site is bought by area. Carpet is not. It comes off a roll twelve feet wide, and you buy however many linear feet your rooms need — which means the geometry of your house is doing the estimating.
A room twelve feet wide or less is the best case: one strip, no seam, and waste is only the difference between the room width and the roll. A room thirteen feet wide needs a second strip to cover that extra foot, and the second strip is twelve feet wide like the first one. You pay for eleven feet of carpet you will never see.
This is why carpet quotes look padded next to laminate quotes for the same floor, and why arguing with the installer about it gets you nowhere. It is not their margin. It is the loom.
0%
12 ft wide room
One strip, no seam, nothing wasted
20%
13 × 20, roll across
Two strips of 13 ft
85%
13 × 20, roll along
Two strips of 20 ft — same room
15%
13 × 20, 15 ft roll
Back to a single strip
The direction decision, and how to win it
Given a room and a roll width there are two ways to lay the strips, and they are rarely equal. The calculator tries both and tells you the difference, because nobody else will: the installer decides this on the day, usually by habit, and the waste is already in your price by then.
There are constraints, though, and they are worth knowing before you insist on the cheaper option.
Pile direction has to be consistent. Carpet fibres lean one way, and two pieces laid in opposite directions look like different shades under the same light. So every strip in a room runs the same way, and an offcut cannot simply be rotated to fit.
Seams have rules. They should run away from the main window rather than across the light, and they should never land in a doorway or a traffic lane, where feet work at the join until it shows. A layout that saves material and puts a seam across the middle of a sitting room is not a saving.
Continuity between rooms matters where carpet runs through a doorway without a transition. That can force a direction on a whole floor.
Stairs, which are priced per step for a reason
Every carpet fitter in the country quotes stairs by the step rather than by area, and the reason is simple: a stair takes several times longer per square foot than a flat floor. Each tread is cut individually, fitted around the nosing, and fastened at both the back of the tread and the bottom of the riser.
The material is straightforward arithmetic — rise plus tread plus the nosing overhang, times the width of the stair — which works out at roughly 1.58 linear feet per step, or about six square feet on a standard three-foot flight once waste is included.
| Waterfall | Upholstered (cap and band) | |
|---|---|---|
| How it looks | Carpet flows over the nosing in a smooth curve | Wrapped tight to the shape of every step |
| Material | Less — one continuous run | More, and every step is cut separately |
| Labour | Faster | Considerably slower |
| Wear | Nosing takes the traffic through the pile | Better supported at the edge |
| Typical use | Almost every residential stair | Open-sided stairs and higher-end work |
The pad matters more than people think
Pad is the cheapest component of a carpet job and the one that most affects how long the carpet lasts. It is also the one that gets downgraded to save money, which is close to exactly backwards.
The figure to look at is density, not thickness. Density is weight per cubic foot, and it describes how well the pad resists being crushed permanently. A dense eight-pound pad at seven sixteenths of an inch outlasts a soft six-pound at half an inch, and it protects the carpet backing from the impact of every footstep.
| Pad | Density | Per ft² | Where |
|---|---|---|---|
| Standard — 7/16 in, 6 lb | 6 lb | $0.55 | The usual residential pad. Adequate under a mid-range carpet in a bedroom. |
| Upgraded — 1/2 in, 8 lb | 8 lb | $0.85 | Denser rather than thicker, which is what actually extends carpet life. The cheapest upgrade on this page by a distance. |
| High density — 3/8 in, 8 lb | 8 lb | $0.95 | Thinner and firmer, for stairs and heavy traffic. A thick soft pad on a stair lets the carpet flex over the nosing until it wears through. |
MaterialsEstimator, Carpet roll width and installation survey · checked 2026-09-16
Reusing old pad is almost never worth it. It has compressed permanently where the furniture and the traffic were, so a new carpet goes down on a surface that is already uneven — and it voids most carpet warranties, which is a poor trade for the least expensive line on the quote.
What separates a good installation from a cheap one
Carpet is the flooring where the fitter matters most. Laminate either clicks together or it does not; carpet can be installed badly in ways that look fine for a year.
The single biggest one is power stretching. Carpet has to be tensioned across the room with a pole-braced stretcher before it is hooked onto the tack strip. A carpet fitted only with a knee kicker — the small tool meant for edges and cupboards — relaxes over the following months and buckles into ripples. The only fix is to lift it and do it again properly.
The second is seam placement, covered above, and the third is simply preparation: old tack strip removed rather than reused, staples pulled, the subfloor checked and squeaks fixed while the floor is open.
Worth asking before you book
- Do you power stretch, or knee kick? The answer tells you most of what you need to know.
- Where will the seams fall, and which way does the pile run?
- Is new tack strip included, or are you reusing what is there?
- Is the old carpet and pad removal and disposal in the price?
- Are stairs quoted per step, and is that waterfall or upholstered?
- Who moves the furniture, and is that in the quote?
What carpet installation costs per square foot, and where the money goes
Carpet spans a wider price range than almost anything else here — builder grade and wool differ by a factor of six — but the structure of the bill is consistent.
Builder grade
What goes into rentals and spec houses. It mats down in the traffic lanes within a couple of years and no cleaning brings it back.
$1.1–$2.8 per ft² · lasts 3–5 years
Mid range
Denser pile and a better backing. The sensible choice for a bedroom, and the point at which the pad starts mattering more than the carpet.
$2.4–$5.2 per ft² · lasts 7–10 years
Premium
Wool or a high-twist nylon. Worth it on stairs and landings, where the wear is concentrated and replacement is most disruptive.
$5–$12 per ft² · lasts 12–20 years
The arithmetic worth doing is cost per year rather than cost per square foot. Builder grade at a third of the price that lasts a quarter as long is not a saving — it is a deferred payment, plus having the furniture moved out twice.
Where the premium is unambiguous is stairs and landings: the wear is concentrated, and replacing carpet on a stair is the most disruptive part of the job.
Comparing against hard flooring? That calculator prices laminate, vinyl plank and wood the same way — and it has the refinishing option if what is under the carpet turns out to be boards.
Flooring calculatorFive ways this goes wrong
01Estimating carpet by floor area
Carpet comes in 12 ft widths. A 13 ft room needs two strips, so you pay for 24 ft of width to cover 13 — and no amount of careful cutting changes that.
Instead — Work in linear feet off the roll, and check both orientations before accepting a figure.
02Letting the installer pick the direction by habit
On a 13 by 20 room the two orientations differ by 168 square feet of carpet. That decision is usually made on the day, without anyone pricing the alternative.
Instead — Work out both, and raise it before the material is ordered — subject to where the seam has to fall.
03Saving money on the pad
Pad is the cheapest line on the quote and the one that most affects how long the carpet lasts. A soft pad lets the backing flex and break down, especially on stairs.
Instead — Buy density rather than thickness, and go thinner and firmer on the stairs than on the flat.
04Accepting a knee-kicked installation
Without power stretching the carpet relaxes and ripples within a year or two, and the only remedy is lifting and refitting the whole thing.
Instead — Ask the question directly before booking. A fitter who power stretches will say so immediately.
05Putting a seam across the light
A seam running across the light from a window catches it at every join, and a seam in a doorway gets worked at by every footstep until it opens.
Instead — Seams run away from the window and out of traffic lanes, even when that costs a little more material.
How the calculator works it out
- 01Measure each roomLength and width, wall to wall, and into any closet the carpet continues into.
- 02Decide which way the roll runsTry both. Strips along the length or across it produce very different waste, and the difference on one room can be a hundred square feet.
- 03Count the stripsRoom width divided by roll width, rounded up. Two strips means one seam; three means two.
- 04Work out the linear feetStrips times the length they run. That figure times the roll width is what you pay for, whatever the floor measures.
- 05Add the stairs separatelyRise plus tread plus nosing, times the stair width, per step — and add stair waste, because every step is cut individually.
- 06Add pad, tack strip and transitionsPad is cut to fit so the roll width does not apply. Tack strip follows the perimeter; transitions go at every doorway.
Each room is laid out against the roll independently, in both orientations, and the one needing fewer linear feet is chosen — with the alternative kept so the panel can show what the choice saved. Pad is calculated on the real floor area rather than the roll, because it is cut to fit and its own width does not constrain the layout. Stairs are counted per step with their own waste allowance, since each one is cut individually.
Seam placement rules, stretching and pad requirements follow the residential carpet installation standard. Prices split material from labour, and stairs from flat floor. It is all on the sources page, dated.
One thing the calculator deliberately does not do: optimise across rooms. In principle an offcut from one room can fill a closet in another, and a good fitter will do that. It depends on pile direction and on offcut shapes that no web form can know, so the figure here is per-room — which makes it a safe number to order against rather than an optimistic one.
Nothing you type is sent anywhere — the whole calculation runs in your browser.
The words on a carpet quote
Roll width and power stretching are the two that decide what you pay and how long it lasts.
- Roll width
- The fixed width carpet is manufactured in — almost always 12 ft, occasionally 15. You buy linear feet off that roll, which is why the floor area is only half the calculation.
- Seam
- Where two pieces of carpet are joined with heat-activated tape. Unavoidable in any room wider than the roll, and its placement matters more than its existence.
- Pile direction
- The way the fibres lean. Every piece in a room must run the same way or the two sides of a seam look like different colours — which is why offcuts cannot simply be turned to fit.
- Power stretching
- Tensioning the carpet across the room with a pole-braced tool before hooking it to the tack strip. It is what stops ripples appearing in year two, and it is the step cheap installations skip.
- Knee kicker
- The small tool used to nudge carpet onto tack strip near edges and in cupboards. It is a finishing tool, not a substitute for a power stretcher, and a carpet fitted entirely with one will ripple.
- Tack strip
- The thin wooden batten with angled pins that runs around the perimeter and grips the carpet. Sold in 4 ft lengths and replaced with the carpet, not reused.
- Pad density
- Weight per cubic foot, and the figure that matters far more than thickness. A dense 3/8 in pad outlasts a soft 1/2 in one and protects the carpet better, particularly on stairs.
- Waterfall and upholstered
- The two ways to carpet a stair. Waterfall runs the carpet over the nosing in one smooth piece; upholstered wraps it tightly to the shape of every step, looks better, and uses noticeably more material and time.
Common questions
- How much does carpet installation cost?
- Material typically runs $1.10 to $12 per square foot depending on grade, with installation around $0.80 to $2.40 on top, plus pad and removal of the old carpet. A typical mid-range job on a 300 square foot room lands in the high hundreds to low thousands installed.
- How is carpet measured and sold?
- In linear feet off a roll of fixed width — almost always 12 ft. That means you are buying a rectangle 12 ft wide and however long your rooms require, and the offcuts from that rectangle are yours whether you can use them or not.
- Why does carpet have so much waste?
- Because rooms are not 12 ft wide. A 13 ft room needs a second strip to cover the extra foot, and that strip is a full 12 ft wide on the roll. The waste is a property of the room's proportions against the roll width, not a sign of a careless installer.
- Does the direction the carpet runs matter?
- Enormously, for cost. A 13 by 20 ft room takes 40 linear feet of roll one way and 26 the other — 480 square feet against 312 for the same floor. It matters for appearance too: pile direction must be consistent, so the choice is made once for the whole room.
- How many square feet does a roll of carpet cover?
- A 12 ft roll covers 12 square feet for every linear foot you buy. What matters is how much of that ends up on your floor — anywhere from nearly all of it in a 12 ft wide room to barely two thirds in a badly proportioned one.
- How much carpet do I need for stairs?
- About 1.58 linear feet per step for a waterfall installation — rise plus tread plus nosing — times the width of the stair, plus waste because every step is cut individually. On a standard 3 ft flight that works out near 6 square feet a step.
- Are seams in carpet visible?
- A well-placed seam in a well-chosen carpet is close to invisible; a badly placed one never stops being obvious. Seams should run with the light from the main window rather than across it, and should never land in a doorway or a traffic lane where feet will work at them.
- What carpet pad should I use?
- Density matters more than thickness. A dense 8 lb pad at 7/16 in outperforms a soft 6 lb at 1/2 in, and it is the cheapest upgrade available on a carpet job. On stairs go thinner and firmer still — a thick soft pad lets the carpet flex over the nosing until it wears through at the edge.
- Can I reuse my old carpet pad?
- Almost never worth it. Pad compresses permanently where furniture and feet have been, so reusing it puts a new carpet on a surface that is already uneven, and it voids most carpet warranties. It is also the cheapest component of the job.
- Why does my carpet have ripples?
- It was not power stretched. A carpet has to be tensioned across the room with a pole-braced stretcher before being hooked onto the tack strip; one fitted with a knee kicker alone relaxes and buckles within a year or two. The remedy is to lift it and stretch it properly.
- Is a 15 foot roll worth asking for?
- On a wide room, yes — it can turn a two-strip layout into one, removing both a seam and a great deal of waste. It is only made in some ranges, so it is a question to ask before choosing the style rather than after.
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About the author
Pablo Ruiz Quintero — Editor
Editor of MaterialsEstimator. Decides which documents count as a source, what every default value is, and where the line sits between what the reader parses and what the engines compute.
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