Reference data · 2026
What a pool actually costs per year
Every figure on this page is computed, not surveyed. The model, its rates and its assumptions are all stated below, and the same code runs the cost of ownership calculator — so you can put your own electricity rate and pool size in and get a figure built the same way. Free to cite and reuse with attribution.
The short answer
$2,226 per year
A 20,000-gallon in-ground pool, six-month season, no heater, maintained by the owner — about $185 a month averaged across the year. Add a gas heater and it becomes $3,426. Hand the work to a service company and it becomes $4,396. Purchase price is excluded throughout — this is what the pool costs to run.
Annual cost by pool size and climate
In-ground, owner-maintained, unheated, at $0.13/kWh. Climate is the lever people underestimate: a warm-climate pool never closes, so it runs its pump and burns chemicals for twelve months instead of four.
| Pool volume | Warm (12-mo season) | Mixed (6-mo season) | Cold (4-mo season) |
|---|---|---|---|
| 10,000 gal 12 × 24 ft, above-ground or small plunge | $1,681 | $1,584 | $1,502 |
| 15,000 gal 14 × 28 ft in-ground | $2,182 | $1,962 | $1,838 |
| 20,000 gal 16 × 32 ft in-ground — US median | $2,518 | $2,226 | $2,079 |
| 25,000 gal 18 × 36 ft in-ground | $3,018 | $2,603 | $2,415 |
| 30,000 gal 20 × 40 ft in-ground | $3,355 | $2,867 | $2,655 |
| 40,000 gal 20 × 44 ft, deep end | $4,191 | $3,509 | $3,231 |
Season length by climate: warm 12 months, mixed 6, cold 4. Pump size is estimated from volume (1.0 HP under 15k gal, 1.5 under 25k, 2.0 under 40k, 2.5 above).
Where the money goes
The same 20,000-gallon mixed-climate pool, broken into its lines. The repair reserve is the one most owners never budget — it is not a bill that arrives monthly, it is the money that has to exist when the pump fails.
| Line item | Per year | Share |
|---|---|---|
| Electricity (pump) 1.5 HP single-speed, 8 h/day in season, 3 h/day off-season, at $0.13/kWh | $339 | 15% |
| Chemicals Liquid chlorine, acid, occasional CYA and calcium — 20% of the in-season rate during the off-season | $432 | 19% |
| Water top-off 25% of pool volume per season lost to evaporation, splash-out and backwash, at $5 per 1,000 gal | $25 | 1% |
| Test kit + supplies $15/mo — reagents, brush heads, filter cleaner. Zero if a service company covers it | $180 | 8% |
| Opening + closing DIY: winter cover amortization, plugs, closing chemicals | $150 | 7% |
| Repair reserve Pump, heater, filter and surface replacement spread across their service life | $1,100 | 49% |
| Total | $2,226 | 100% |
Heating is absent from this table because the baseline pool is unheated. See the next table for what a heater adds.
What each decision costs
One variable changed at a time against the same baseline. This is the table worth reading before signing anything: the equipment decisions made once, at install, set most of the annual number for the next fifteen years.
| Decision | Per year | vs baseline |
|---|---|---|
| Salt system instead of liquid chlorine Cell amortized at $600 / 4 yrs | $2,111 | −$115 |
| Above-ground instead of in-ground Lower reserve, shorter pool lifespan | $1,656 | −$570 |
| Baseline — in-ground, DIY, unheated 20,000 gal, 6-month season | $2,226 | — |
| Add a heat pump 5 heated months, COP roughly 3× gas | $2,626 | +$400 |
| Add a gas heater 5 heated months at about $1.50/therm | $3,426 | +$1,200 |
| Hire a full-service company $150/mo, includes chemicals and supplies | $4,396 | +$2,170 |
Baseline: 20,000 gal in-ground, mixed climate, liquid chlorine, no heater, owner-maintained.
Method and assumptions
Every number above is produced by one function, run with different inputs. Nothing is transcribed from a price list, and no figure is a range dressed up as a point estimate — where the real world varies, the variation is an input you can change rather than a hedge in the copy.
Rates used: electricity $0.13/kWh, water $5.00 per 1,000 gallons, full pool service $150/month, gas at roughly $1.50/therm. These are national averages; the spread between regions is wider than the spread between pool sizes.
Pump: single-speed, sized from volume, 8 hours a day in season and 3 hours a day off-season, motor efficiency 85%. A variable-speed pump on the same pool cuts the electricity line substantially — it is the largest controllable saving on the list after the cover.
Chemicals: $0.003 per gallon per month on liquid chlorine, $0.0022 on a salt system with cell replacement amortized in. Off-season runs at 20% of the in-season rate.
Water: 25% of pool volume replaced per active season, covering evaporation, splash-out and backwash. This sits at the conservative end of the published range for uncovered pools.
Repair reserve: $500 plus $30 per 1,000 gallons for in-ground, $300 plus $15 for above-ground. This tracks the industry rule of thumb of budgeting 2–3% of pool value a year against pump, filter, heater and surface replacement.
Excluded: purchase and installation price, financing, property tax and insurance changes, and water-feature or automation equipment. Including a purchase price would make the headline number about one household's mortgage rather than about pools.
Scope: United States, US dollars, residential pools. The model is not calibrated for commercial pools or for markets with different energy and water pricing structures.
Want the figure for your pool rather than the median one? Put your own volume, climate, rates and equipment into the cost of ownership calculator. For a monthly view of chemicals and electricity only, use the maintenance cost calculator, and for heating alone, the heating cost calculator.
Cite or republish this data
The tables are free to reproduce — in an article, a listing, a client handout or a school project — under CC BY 4.0, which asks only for a credit line back to this page. Journalists: the numbers regenerate whenever the underlying rates change, so a link stays accurate where a screenshot does not.
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Cost figures from “What a Pool Actually Costs Per Year”, mypool.tools, 2026. https://mypool.tools/pool-cost-report
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<p>Cost figures from <a href="https://mypool.tools/pool-cost-report">What a Pool Actually Costs Per Year</a> by mypool.tools</p>Running a pool site of your own? The calculators behind these figures can be embedded on your pages in one line of HTML — free, no signup. Questions about the model, or want a cut of the data for a specific region? hello@mypool.tools.
Questions
How much does a swimming pool cost per year?
For a 20,000-gallon in-ground pool maintained by the owner in a six-month climate, this model puts the running cost at about $2,226 a year — roughly $185 a month averaged across twelve months. Adding a gas heater takes it to about $3,426, and handing the work to a full-service company takes it to about $4,396. None of these figures include the purchase price of the pool.
What is the single biggest cost of owning a pool?
For an unheated pool it is the repair reserve — the money that has to exist before the pump, filter, heater or surface fails. It does not appear on a monthly bill, which is why it is the line most owners leave out. For a heated pool in a cold climate, heating overtakes it: a gas heater in a cold-winter region can cost more per year than every other line combined.
Is a saltwater pool cheaper to run?
Slightly, on this model — about $115 a year for a 20,000-gallon pool, with the cell replacement already amortized into it. A salt system is a chlorine system that makes its own chlorine; the saving comes from buying less liquid chlorine, not from using less chlorine. The conversion itself runs about $1,000–$2,500 and pays back over years, not months.
How much does a pool heater add to the bill?
On this model a gas heater adds about $1,200 a year to a 20,000-gallon pool over a five-month heated season, and a heat pump adds about $400. Heat pumps run at a COP of roughly 3.5–5.0 but lose output below about 50°F ambient, so the gap narrows in a cold shoulder season.
Does a pool cover actually save money?
Yes, and it is the cheapest lever on the list. Most of a pool's heat leaves through the surface, so a cover cuts heating cost by roughly half. It also reduces evaporation, which cuts both the water top-off line and the chemical line, since evaporating water carries chlorine off with it.
Why is your figure different from the quote I was given?
Local rates. Electricity, water and pool-service pricing vary more between regions than any formula does, and this page uses national averages ($0.13/kWh, $5 per 1,000 gal, $150/mo service). Put your own rates into the calculator linked below and the model recalculates against them.