Pools
Pool maintenance cost
Everybody budgets a pool as chemicals, and on most pools the chemicals are not the big one. A 16 × 32 ft pool costs about $1,634 a year to run — $589 of it the pump and $438 the chemistry. The pump is also the only line that can be cut by most of its value without changing anything about how the pool is used, because power follows the cube of speed and most of the runtime is habit.
Written and edited by Pablo Ruiz Quintero
Last reviewed 2026-09-22 · Nothing you type leaves your browser
It is not the chlorine
Everybody budgets a pool as chemicals. On most pools the pump costs more than the chemistry, and the largest part of that is circulation the water never needed.
Inside the walls.
Inside the walls.
Length times width, and nothing to argue about. Most inground pools and every lap pool.
Gunite and concrete pools
Water depth.
The pump
The biggest line, and the only one that can be cut by most of its value without changing anything about how the pool is used.
One speed, flat out, every hour it runs. It is what nearly every pool built before about 2015 has, it is the largest line on the electricity bill, and it is no longer legal to fit a new one on most pools.
One turnover of this pool takes 4.9 hours at this pump's duty speed. Anything more is habit.
Off your own bill. The national average is around 17 cents.
How it is run
The usual temperate season, and the default here.
Cheaper to run, dearer to install, and the cell is a consumable.
The single biggest lever on this page if the pool is heated.
An unheated pool is a different animal financially.
About 65 hours a year of your own time.
For what evaporates.
Honestly. Everybody in the household, every time anybody gets in. It is the denominator of the only figure that answers whether the pool is worth it.
6 months a year
$1,634/yr
$136 a month · $33 a swim · the pump is 36% of it
$33 a swim, at 50 swims a year
It is an uncomfortable number and nobody publishes it, which is why it is here. It is also the only figure that answers the question actually being asked — and the cheapest way to improve it is to swim more, not to spend less.
Power follows the cube of speed
Half the speed, an eighth of the power
Flow rises with pump speed; power rises with the cube of it. So running slowly for twice as long moves the same water for a quarter of the energy. It is the whole reason variable-speed pumps exist and the reason they pay for themselves.
| Same turnover with | kWh | A year | Pays back |
|---|---|---|---|
| Single speed · yours | 1,710 | $291 | — |
| Two speed | 657 | $112 | 1.5 yr |
| Variable speed | 428 | $73 | 3.8 yr |
Each row does the same daily turnover, which is the only fair comparison — the slower pumps simply take longer over it.
Where the year goes
Every line on the same scale.
A year of running it
- Running the pump, 3,466 kWh
1.9 kW for 10 hours a day over 6 months. One turnover of this pool takes 4.9 hours at this speed — everything past that is circulation the water did not ask for.$589 - Salt, acid, stabiliser and shock
Cheaper to run than tablets, and the cell underneath it is a consumable.$298 - Salt cell, set aside
About $700 every 5 years. It is the largest recurring item a salt pool has and it never appears in a comparison against tablets.$140 - Reserve for what wears out
The pump, the filter and the rest, divided by the years they last. Nothing breaks in an average year, and then something does.$505 - Water lost to evaporation
A quarter of an inch a day off an uncovered pool. The water is the cheap half of what a cover saves.$102
In order of what it is worth doing
Cheapest first, which is not how anybody is ever sold it.
- 01Turn the runtime down to one turnover — 4.9 hours here. Costs nothing, and on most pools it is the largest single saving available.
- 02Put a cover on. It pays back on water alone slowly, and on heat almost immediately.
- 03Change the pump for a variable-speed one. About 3.8 years here, and then it keeps paying.
- 04Set the reserve aside as a standing amount rather than discovering it. The pump, the filter and the heater all have a date.
- 05Only then consider whether the service is worth what it costs in time.
The turnover time comes from what the pool actually holds — which is the number most people have wrong, because the average-depth formula runs about 17 per cent high on a pool with a hopper bottom.
Worth knowing
- The biggest line is the pump, not the chemicals: $589 of electricity against $438 of chemistry. That is 36 per cent of the running cost coming out of a motor nobody thinks about, and it is the only line here that can be cut by most of its value without changing anything about how the pool is used.
- Flow rises with pump speed and power rises with the CUBE of it. Run at half speed and the pump draws an eighth of the power while moving half the water — so the same daily turnover takes twice as long and a quarter of the energy. Changing this pump for a variable-speed one saves about $218 a year and pays for itself in 3.8 years, after which it is money the pool stops costing. A two speed pump actually pays back sooner — 1.5 years against 3.8 — because it costs so much less to fit for most of the same saving; it is also getting hard to buy, because the federal standard has moved past it.
- At 10 hours a day this pump moves 2 times the water the pool needs turning over. That is $298 a year of circulation nobody asked for — and it is bought back by changing a timer, which costs nothing. Do that before spending anything on a pump: together with a variable-speed motor the two come to about $516 a year, of which the free half is the larger.
- No cover. That is 14,554 gallons a year evaporating — about $102 of water, which is nothing. The water bill is the small half of what a cover saves; the other half only shows up if the pool is heated. A cover would cut the evaporation to about 5,094 gallons.
- A salt cell is a wearing part, not a fixture. It lasts 5 years or so and costs about $700 to replace, which is $140 a year set aside whether or not anybody is setting it aside. It is the largest recurring item a salt pool has and it never appears in a comparison against tablets.
- $505 a year of this is reserve — the pump, the filter and the rest divided by the years they last. Nothing breaks in an average year, and then something does. A pool that has never cost that is a pool that has not yet had its turn.
- $33 a swim at 50 swims a year. It is an uncomfortable number and it is the only one that answers the question people are actually asking, which is whether the pool is worth it. Swim twice as often and it halves — which makes using the pool the cheapest thing on this page.
- Doing it yourself instead of paying for a weekly visit saves $870 a year and costs about 65 hours. That works out at $13 an hour for the time you are buying back, which is the honest way to decide it.
On this page — 4 sections
Everybody budgets the chlorine
The short version
- The pump is the biggest line on an unheated pool — $589 against $438 of chemistry.
- Power follows the cube of speed. Half speed, an eighth of the power, a quarter of the energy for the same turnover.
- Most of the runtime is habit. One turnover here is 4.9 hours, and turning the timer down is free.
- $33 a swim. The figure nobody publishes, and the only one that answers the question.
Ask anybody what a pool costs to run and the answer comes back in chemicals. Chlorine, shock, acid, the bucket of tablets in the shed. It is what you buy, it is what you carry, it is what you think about.
It is not where the money goes. On this pool the chemistry is $438 a year and the pump is $589 — a motor in a box by the fence that nobody has looked at since it was installed.
| The pump | $589 | 10 h a day at 1.9 kW |
| Chemistry | $298 | A six-month salt season |
| Salt cell, set aside | $140 | $700 every 5 years |
| Reserve for what wears out | $505 | Pump, filter, cleaner, valves |
| Water lost to evaporation | $102 | Uncovered, a quarter inch a day |
| A year | $1,634 | $136 a month, $33 a swim |
A 16 × 32 ft salt pool, six-month season, single-speed pump at ten hours a day, no cover, no heat, looked after by its owner. Electricity at 17 cents.
MaterialsEstimator, Pool running cost survey — chemicals, service, water and reserve · checked 2026-09-22
Power follows the cube of speed
This is the part that makes the pump worth understanding, and it is physics rather than a sales pitch.
For any centrifugal pump, flow rises in proportion to speed, and power rises with the cube of it. Run a pump at half speed and it moves half as much water — and draws an eighth of the power.
Which means, for the same daily turnover: twice as long, and a quarter of the energy. Not a tenth off. Not fifteen per cent. A quarter of what it was.
| Same turnover with | Speed | kWh a year | Cost | Pays back in |
|---|---|---|---|---|
| Single speed | 100% | 1,710 | $291 | — |
| Two speed | 62% | 657 | $112 | 1.5 years |
| Variable speed | 50% | 428 | $73 | 3.8 years |
Each row moves the same water in a day. The slow ones simply take longer, and the cube law does the rest. This is also why the federal efficiency standard has made variable-speed the default replacement on most pools.
Hydraulic Institute, and US Department of Energy, Centrifugal pump affinity laws, and the DOE efficiency standard for dedicated-purpose pool pumps · checked 2026-09-22
Heating is not a line. It is a different bill.
Everything above describes an unheated pool, and an unheated pool is an affordable thing. Heating changes the arithmetic so completely that it is better thought of as a separate decision than as an option.
This pool costs about $2,856 a year to heat on gas without a cover — more than everything else on the page put together. And nearly all of it is not warming the pool. It is replacing heat that left overnight.
| Heated, covered | Heated, uncovered | |
|---|---|---|
| Heating | $1,143 | $2,856 |
| Everything else | $1,949 | $2,016 |
| A year | $3,092 | $4,872 |
| A month | $258 | $406 |
| A swim | $62 | $97 |
| What the cover costs | A few hundred dollars, once | — |
A cover is not a comfort item on a heated pool. It is the difference between a heating bill and a heating problem, and it pays for itself inside a season.
The other lever is the heater itself. A heat pump moves heat rather than making it, so it uses a fraction of the energy for the same degrees — but it works slowly and it stops working well when the air is cold, which is exactly when a pool most wants heating. Gas is the opposite: expensive per degree and available on demand.
Before deciding to heat a pool at all
- Work out the unheated cost first. Heating is usually larger than everything else combined, so it deserves its own decision.
- Budget a cover in the same breath. Heating an uncovered pool is the most expensive way to be warm that a garden can offer.
- Check how many extra swims the heat actually buys. If it extends the season by six weeks and nobody swims in them, the cost per swim goes the wrong way.
- Consider heating to a lower temperature. Every degree costs the same to hold, so 82°F is meaningfully cheaper than 86°F and most people cannot tell.
- For a heat pump, look at the local overnight temperatures in the shoulder months. It is a fine machine in mild air and a poor one in cold.
- Ask whether solar is an option. It is slow and weather-dependent and its running cost is nil.
$1,634
A year, unheated
$136 a month
$4,872
A year, heated and uncovered
$406 a month
$1,713
What a cover saves
On heating alone, every year
$33
A swim, unheated
At 50 swims a year
US Energy Information Administration, Electric Power Monthly, average residential price by state · checked 2026-09-21
What goes wrong
01Budgeting a pool as chemicals
Chemistry is $438 of a $1,634 year. The pump is $589, and it is the one nobody looks at.
Instead — Read the pump's wattage and its timer, and price it off your own electricity rate. It is the only line here that is genuinely calculable.
02Running the pump because it has always run that long
One turnover on this pool is 4.9 hours. Ten is normal and costs about $298 a year more for water that was already clean.
Instead — Work out the turnover from what the pool actually holds and set the timer to it. It is free and it is usually the biggest single saving available.
03Dismissing a variable-speed pump as a gadget
Power follows the cube of speed, so half speed for twice as long is a quarter of the energy. That is $73 a year against $291.
Instead — Price it as an investment with a 3.8-year payback — and check a two-speed first, which pays back in 1.5 for most of the same benefit.
04Heating an uncovered pool
Evaporation is where most of a pool's heat goes. Uncovered costs $2,856 a year here against $1,143 covered — a difference of $1,713.
Instead — Budget the cover before the heater. On a heated pool it pays for itself inside a season and it is not close.
05Leaving the salt cell out of a salt-versus-tablets comparison
The cell lasts about 5 years and costs around $700, which is $140 a year. It is the largest recurring item a salt pool has.
Instead — Include it. Salt is still cheaper to run, but by much less than the comparison usually suggests.
06Having no reserve for equipment
The pump, the filter and the rest all have a date. That is $505 a year that does not happen in most years and then happens all at once.
Instead — Set it aside as a standing amount. A pool that has never cost you this has not yet had its turn.
07Trusting a monthly figure with no season behind it
A pool's costs are annual and lumpy — chemistry and electricity stop out of season, and the reserve belongs to no month at all. A monthly number without a season length cannot be checked.
Instead — Work out the year and divide it yourself, so you know which months the figure is actually describing.
08Never working out the cost per swim
It is the only figure that answers whether the pool is worth what it costs, and at $33 a swim it is uncomfortable enough that nobody publishes it.
Instead — Count honestly, divide, and note that the cheapest way to improve the number is to use the pool more rather than to spend less on it.
- 01Find what the pool holdsEvery chemical dose and the turnover time both scale by it, and the average-depth formula gets it wrong on most inground pools.
- 02Work out one turnoverGallons divided by the pump's flow. That is what the water needs, and it is the standard to judge the runtime against.
- 03Read the pump's actual runtime off the timerNot what you think it is. Most pools run two or three times a turnover out of habit, and it is the largest single saving on the page.
- 04Price the electricity off your own billKilowatt-hours times the rate. This is the biggest line on most pools and the only one that is genuinely calculable rather than surveyed.
- 05Add the chemistry, honestlyA season of salt or tablets, plus acid and stabiliser — and on a salt pool the cell divided by the years it lasts.
- 06Set aside the reserveThe pump, the filter and the heater divided by their lives. Nothing breaks in an average year, and then something does.
- 07Divide by how often anybody swimsCount honestly. It is the only figure that answers the question actually being asked.
The turnover time, every chemical dose and the water lost to evaporation all come out of what the pool actually holds — and the average-depth formula everybody uses runs about 17 per cent high on a pool with a hopper bottom.
Everything here scales by the gallons- Turnover
- Passing the whole volume of the pool through the filter once. It is what the pump is for, it takes 4.9 hours on this pool at full speed, and it is the standard against which every runtime should be judged.
- Affinity laws
- The relationships governing a centrifugal pump: flow rises in proportion to speed, head with the square of it, and power with the cube. The cube is why a slow pump running longer is so much cheaper for the same work.
- Variable-speed pump
- A permanent-magnet motor that runs at any commanded speed. Because of the cube law it does the same daily turnover for roughly a quarter of the energy, which is why federal efficiency rules have made it the default replacement.
- Duty speed
- The speed a pump is run at for the routine daily turnover, as opposed to the high speed used for vacuuming or backwashing. On a variable-speed pump it is usually around half.
- Reserve
- Money set aside for equipment that will certainly fail but not this year — the pump, the filter, the heater, the cleaner. It is about $505 a year on this pool, and it is the line everybody discovers rather than budgets.
- Salt cell
- The chlorine generator on a salt pool. It is a wearing part with a life of 5 years or so and a replacement cost around $700, which never appears in a comparison against tablets.
- Evaporation
- Water leaving the pool as vapour — about 0.25 of an inch a day from an uncovered pool in summer. It is a small water bill and, on a heated pool, an enormous heat bill.
- Cover
- A solar or safety cover over the water. It cuts evaporation by roughly two thirds and heat loss by more, which makes it the largest single lever on a heated pool's running cost.
- Therm
- A hundred thousand BTU of gas, the unit a gas bill is written in. A pool heater is quoted in BTU per hour, so the two convert directly.
- Coefficient of performance
- How many units of heat a heat pump moves per unit of electricity it uses. A pool heat pump runs around five, which is why it costs a fraction of gas to run and takes far longer to get there.
- Stabiliser
- Cyanuric acid, which protects chlorine from sunlight. Tablets carry it with them, so on a tablet pool it accumulates until the only remedy is replacing water.
- Cost per swim
- The annual running cost divided by how often anybody actually gets in. It is not published anywhere because it is unflattering, and it is the only figure that answers whether the pool is worth what it costs.
Common questions
- How much does it cost to maintain a pool per year?
- For a 16 × 32 ft salt pool over a six-month season, looked after yourself and not heated: about $1,634 a year, or $136 a month. The pump is $589 of that, chemistry is $438 and the reserve for equipment that will eventually fail is $505. Heat it and the same pool is about $4,872; pay for a weekly service instead of doing it yourself and it is $2,504.
- What is the biggest cost of owning a pool?
- The pump, on almost any pool that is not heated — $589 a year here against $438 of chemistry. Everybody budgets a pool as chlorine and it is very rarely the big one. If the pool is heated, heating dwarfs everything: $2,856 a year uncovered on gas, which is more than the entire rest of the bill.
- How long should I run my pool pump?
- Long enough for one turnover, which on this pool is 4.9 hours at full speed. Most pools are run for eight to twelve out of habit — at ten hours this one spends about $298 a year circulating water that was already clean. Turning the timer down is free and it is usually the largest single saving available to a pool owner.
- Is a variable-speed pool pump worth it?
- Yes, and the reason is physics rather than marketing. Flow rises in proportion to pump speed but power rises with the CUBE of it — so at half speed the motor draws an eighth of the power while moving half the water, and the same daily turnover takes twice as long and a quarter of the energy. On this pool that is $73 a year against $291, paying back in about 3.8 years. A two-speed pump pays back faster still at 1.5 years, though they are increasingly hard to buy.
- How much does it cost to heat a pool?
- More than everything else combined. This pool on gas, uncovered, costs about $2,856 a year to heat — and almost all of that is replacing heat that left through the surface overnight. With a cover it drops to roughly $1,143. A heat pump uses a fraction of the energy because it moves heat rather than making it, but it takes far longer to raise the temperature and does not work well in cold air.
- Is a pool cover worth the money?
- On an unheated pool it saves water and a little chemistry — real, but small. On a heated pool it is the single largest lever there is: the difference here is about $1,713 a year, because evaporation is where most of a pool's heat goes. If you heat a pool and do not cover it, most of what you are paying for is warming the sky.
- Is salt cheaper than chlorine?
- To run, yes — noticeably. To own, less than people think, because the cell is a consumable: about $700 every 5 years, which is $140 a year set aside whether or not anybody sets it aside. That is the line that never appears in a salt-versus-tablets comparison, and including it closes most of the gap.
- Should I pay for a pool service?
- It is about $870 a year for a weekly visit over a six-month season, and doing it yourself takes roughly 65 hours. That works out at about $13 an hour for the time you are buying back — which is the honest way to decide it, rather than as a question of whether you can afford it.
- What does a pool cost per month?
- About $136 on this pool, unheated and self-maintained — but be careful with monthly figures, including that one. A pool's costs are annual and lumpy: the chemistry and the electricity stop out of season, and the reserve does not happen in any particular month at all. A monthly number quoted without a season length behind it cannot be checked, and most of the published ones are exactly that.
- What is the cost per swim?
- About $33 on this pool at 50 swims a year. It is not a figure anybody publishes, because it is unflattering — and it is the only one that answers the question people are actually asking. The encouraging half is that the denominator is the easiest thing on the page to change: swimming twice as often halves it, and costs nothing at all.
- What should I budget for repairs?
- About $505 a year on an unheated pool — pump, filter, and its media, robot or suction cleaner, valves, seals, lights and actuators, each divided by the years it lasts. Nothing breaks in an average year, which is exactly why this gets left out and why it arrives as a shock. A pool that has never cost you this is a pool that has not yet had its turn.
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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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