The short answer
Turning over a 20,000 gallon pool once a day costs about $28.67 a month with a small single-speed pump (WEF 3.8) and $16.51 with a variable-speed pump (WEF 6.6), at the U.S. average electricity rate of 18.16¢ per kWh (August 2026). Over a 5-month season that's $143.37 vs $82.55.
The same pool in every state
A 20,000 gallon pool, 1 turnover a day with a WEF 3.8 pump, 30 days a month for 5 months, at each state's average residential rate (August 2026).
| Alabama | $25.78 | $128.92 | 16.33¢ |
|---|---|---|---|
| Alaska | $46.44 | $232.18 | 29.41¢ |
| Arizona | $23.76 | $118.82 | 15.05¢ |
| Arkansas | $22.69 | $113.45 | 14.37¢ |
| California | $46.97 | $234.87 | 29.75¢ |
| Colorado | $27.11 | $135.55 | 17.17¢ |
| Connecticut | $38.70 | $193.50 | 24.51¢ |
| Delaware | $29.53 | $147.63 | 18.70¢ |
| District of Columbia | $41.02 | $205.11 | 25.98¢ |
| Florida | $23.67 | $118.34 | 14.99¢ |
| Georgia | $25.11 | $125.53 | 15.90¢ |
| Hawaii | $74.49 | $372.47 | 47.18¢ |
| Idaho | $21.11 | $105.55 | 13.37¢ |
| Illinois | $30.51 | $152.53 | 19.32¢ |
| Indiana | $26.87 | $134.37 | 17.02¢ |
| Iowa | $26.94 | $134.68 | 17.06¢ |
| Kansas | $24.43 | $122.13 | 15.47¢ |
| Kentucky | $21.79 | $108.95 | 13.80¢ |
| Louisiana | $20.32 | $101.61 | 12.87¢ |
| Maine | $50.70 | $253.50 | 32.11¢ |
| Maryland | $33.79 | $168.95 | 21.40¢ |
| Massachusetts | $48.13 | $240.63 | 30.48¢ |
| Michigan | $36.30 | $181.50 | 22.99¢ |
| Minnesota | $27.16 | $135.79 | 17.20¢ |
| Mississippi | $22.78 | $113.92 | 14.43¢ |
| Missouri | $25.29 | $126.47 | 16.02¢ |
| Montana | $24.58 | $122.92 | 15.57¢ |
| Nebraska | $21.38 | $106.89 | 13.54¢ |
| Nevada | $20.08 | $100.42 | 12.72¢ |
| New Hampshire | $43.64 | $218.21 | 27.64¢ |
| New Jersey | $38.86 | $194.29 | 24.61¢ |
| New Mexico | $26.07 | $130.34 | 16.51¢ |
| New York | $45.24 | $226.18 | 28.65¢ |
| North Carolina | $23.61 | $118.03 | 14.95¢ |
| North Dakota | $21.02 | $105.08 | 13.31¢ |
| Ohio | $30.60 | $153.00 | 19.38¢ |
| Oklahoma | $23.40 | $117.00 | 14.82¢ |
| Oregon | $25.14 | $125.68 | 15.92¢ |
| Pennsylvania | $34.37 | $171.87 | 21.77¢ |
| Rhode Island | $44.49 | $222.47 | 28.18¢ |
| South Carolina | $24.88 | $124.42 | 15.76¢ |
| South Dakota | $23.92 | $119.61 | 15.15¢ |
| Tennessee | $21.19 | $105.95 | 13.42¢ |
| Texas | $25.12 | $125.61 | 15.91¢ |
| Utah | $21.02 | $105.08 | 13.31¢ |
| Vermont | $37.64 | $188.21 | 23.84¢ |
| Virginia | $27.85 | $139.26 | 17.64¢ |
| Washington | $23.10 | $115.50 | 14.63¢ |
| West Virginia | $25.75 | $128.76 | 16.31¢ |
| Wisconsin | $30.65 | $153.24 | 19.41¢ |
| Wyoming | $22.78 | $113.92 | 14.43¢ |
How it works
The formula
cost = kWh × days × rate
Assumptions
- WEF (weighted energy factor) is the Department of Energy's rating for pool filter pumps since July 2021: thousand gallons pumped per kWh, weighted over the speeds the test uses. We take your daily gallons at that rate; a pump run at different speeds than the test assumes will differ.
- Presets are DOE's minimums for single-phase self-priming pumps (as published by Natural Resources Canada, which adopted the same rule): −1.30 × ln(hhp) + 2.90 below 0.711 hydraulic horsepower, giving 3.8 at ½ hhp, and −2.30 × ln(hhp) + 6.59 from 0.711 to 2.5 hhp, giving 6.59 at 1 hhp. Most variable-speed pumps beat the minimum; use your pump's own WEF if you have it.
- Older pumps made before July 2021 may be well below these figures.
Worked example: a 20,000 gallon pool
One turnover a day, small single-speed pump at WEF 3.8, 30 days
- 20,000 ÷ (3.8 × 1,000) = 5.26 kWh a day
- × 30 = 157.9 kWh × 18.16¢ = $28.67 a month
- Variable-speed at WEF 6.6: $16.51 a month
Ways to cut the cost
- Run a variable-speed pump slow and long: half the speed takes far less than half the power.
- Keep the filter and baskets clean so the pump isn't pushing against a clog.
- Use a pool cover: less debris and evaporation means less filtering and chemicals.
- Check for a utility rebate before replacing an old single-speed pump.
Questions people ask
How much does it cost to run a pool pump?
For a 20,000 gallon pool turned over once a day, about $28.67 a month with a small single-speed pump (WEF 3.8) at the U.S. average of 18.16¢ per kWh (EIA, August 2026), or $16.51 with a variable-speed pump at WEF 6.6. The same small pump costs $20.08 a month in Nevada and $74.49 in Hawaii.
What is WEF on a pool pump?
The weighted energy factor: how many thousand gallons the pump moves per kWh of electricity (the same number as gallons per watt-hour). Higher is cheaper to run. Every pool filter pump made for the U.S. since July 2021 has a WEF rating; it's in the maker's specifications and the Department of Energy's certification database.
Is a variable-speed pool pump worth it?
Usually. Moving water slowly takes far less power per gallon, which is why variable-speed pumps score much higher WEFs. At the U.S. average rate, going from WEF 3.8 to 6.6 saves about $60.82 over a 5-month season for a 20,000 gallon pool, more with a bigger pool or a longer season. Many utilities offer rebates on them.
How long should I run my pool pump?
Long enough to move the whole pool's volume through the filter at least once a day is a common starting point; your pool pro may advise more in hot weather or heavy use. A variable-speed pump runs longer at low speed and still uses less power.
How many gallons is my pool?
Length × width × average depth × 7.48 for a rectangular pool, in feet. Our YardSums pool volume calculator does round, oval and kidney pools too.