Pool Energy Cost Calculator

kWh per day = (input watts ÷ 1,000) × daily operating hours. Sum the daily kWh for the pump, electric heater, and other devices. Multiply by the electricity rate for daily cost; multiply by active days for annual cost.

Worked example: A pump drawing 900 W for 8 hours uses 0.9 kW × 8 = 7.2 kWh/day. At $0.18/kWh, that is $1.296/day (shown as $1.30). Over 365 days: $473.04. Monthly average: $473.04 ÷ 12 = $39.42.

Additional example: A heat pump drawing 3,000 electrical watts for 4 hours adds 12 kWh/day, or $2.16/day at $0.18/kWh. Combined with the example pump, the total is 19.2 kWh and $3.46/day. Heater runtime varies substantially with weather, pool cover, set temperature, and equipment efficiency; a fixed daily schedule is only an estimate.

Variable-speed pumps change watts and flow together

A variable-speed pump can use much less power at a lower speed, but it may also need more hours to circulate the same volume. Compare total daily kWh at each operating schedule, not wattage alone. The pool turnover time calculator can help compare theoretical circulation volume at different actual flow rates.

Electric resistance heaters and heat pumps are different

For an electric resistance heater, the electrical input generally becomes heat at the equipment. A pool heat pump moves heat from surrounding air, so its heat output can exceed its electrical input. For this calculator, enter the heat pump's electrical input watts, not the thermal output BTU/h. COP (coefficient of performance) is useful when comparing heating performance but is not a substitute for measured power and operating hours. Use the pool heating time calculator for a separate heating-duration estimate.

Gas and propane heating costs are not included

A gas heater's BTU/h fuel input is not electrical watts. Its gas bill must be estimated from fuel consumption, delivered fuel price, and efficiency. You may enter its small electrical auxiliary load separately, but this calculator does not compute gas or propane fuel expense.

Time-of-use electricity pricing needs separate scenarios

If your utility charges different rates at peak and off-peak hours, calculate each schedule separately and add the totals. The calculator assumes one blended rate and does not include demand charges, taxes, fixed service fees, or tiered rate changes.

Seasonal operation and weather matter

Choose the number of active days realistically. Heater run hours vary with temperature, wind, solar exposure, pool cover, and thermostat settings. For a summer-only system, 120 active days may be more useful than 365. The monthly figure is an annualized average, not a prediction for a specific month.

• Entering horsepower instead of watts: Motor shaft horsepower is mechanical output; actual electrical input is different. Check documentation or measure the circuit appropriately.
• Entering a heat pump's BTU/h rating: That is heating output, not electrical consumption. Find the rated input watts or amps/volts with power-factor considerations.
• Counting gas heater fuel as electricity: Gas fuel requires a different cost calculation.
• Assuming maximum watts all day: Variable-speed and cycling equipment often change draw or duty cycle.
• Using a monthly rate without units: Enter dollars per kWh, not cents. For 18 cents enter 0.18.
• Reading monthly average as a peak-season bill: The result divides annual estimated cost by 12, even if equipment runs only part of the year.
• Assuming low energy cost means sufficient filtration: Energy expense and water-quality performance are separate questions.