Pool Energy Cost Calculator
Estimate your swimming pool's monthly and annual energy costs by entering your pump, heater, and lighting specifications along with your local electricity rate. This calculator uses industry-standard formulas to give you an accurate picture of your pool's operating expenses so you can make informed decisions about equipment upgrades and run-time schedules.
Electricity Rate
Pool Pump
Pool Heater (Electric / Heat Pump)
Pool Lighting
Formulas Used
Pump Power (kW):
kW = (HP × 0.7457) ÷ (Motor Efficiency ÷ 100)
0.7457 is the exact conversion factor: 1 HP = 745.7 W
Daily Energy (kWh/day):
kWh/day = kW × Run Hours per Day
Monthly Energy (kWh/month):
kWh/month = kWh/day × 30.44 (average days per month)
Annual Energy (kWh/year):
Pump & Lighting: kWh/day × 365
Heater: kWh/day × (Active Months × 30.44)
Energy Cost:
Cost = kWh × Electricity Rate ($/kWh)
Assumptions
- 1 HP = 0.7457 kW (exact SI conversion per IEEE standard).
- Motor efficiency is the nameplate or measured full-load efficiency; typical single-speed motors run 80–90%.
- A month is treated as 30.44 days (365 ÷ 12) for consistent monthly averaging.
- The pump and lighting are assumed to operate year-round (365 days); adjust run hours seasonally as needed.
- The heater is assumed to operate only during its specified active months.
- Heater power draw entered should be the electrical draw (kW), not BTU output — for electric resistance heaters this is straightforward; for heat pumps, enter the compressor + fan draw (not the equivalent BTU capacity).
- Gas heaters have no electrical energy cost beyond the ignition/controls (~50–100 W) and are not included in this calculator.
- The variable-speed pump savings estimate uses the DOE/ENERGY STAR finding that a properly sized VSP can reduce pump energy by up to 75% compared to a single-speed pump.
- Electricity rate is assumed constant (flat rate); time-of-use (TOU) rate structures will produce different results.
- This calculator does not account for pool cleaner pumps, water features, or automation controllers.