Estimate yearly electricity savings from a variable-speed pool pump using pump watts, run time, electric price, and pool season length.
Advanced options
Table of contents
How to use our Variable Speed Pool Pump Savings Calculator
- Enter Current pump power, Current pump run time, Variable-speed pump power, and Variable-speed pump run time using the daily schedule you actually use or plan to use.
- Enter Electricity price and Pump use. Use dollars per kWh, so 18 cents per kWh is 0.18, and use 365 days only if the pump runs year-round.
- If your electric plan has peak and off-peak prices, open Advanced options and fill all four time-of-use fields: Current pump hours during peak price, Variable-speed pump hours during peak price, Peak electricity price, and Off-peak electricity price.
- Click Calculate and read Estimated yearly electricity savings first. A positive number means the variable-speed setup costs less to run, while a negative number means it costs more with the values entered.
- Sanity-check the output by comparing Current pump yearly electricity cost with your electric bills. If the pump cost is larger than your whole bill for the same season, recheck watts, hours per day, and $ per kWh.
Definitions
W: Watts are a measure of electric power. Higher pump watts mean the pump uses electricity faster.
kWh: A kilowatt-hour is energy use over time. A 1000 W device running for 1 hour uses 1 kWh [1].
$ per kWh: This is the electricity price used to turn energy use into cost. If your bill says 18 cents per kWh, enter 0.18.
Peak electricity price: The higher $ per kWh used during more expensive hours on a time-of-use plan.
Off-peak electricity price: The lower $ per kWh used during cheaper hours on a time-of-use plan.
Pump use: The number of days per year the pool pump runs. This may be 365 for year-round use or fewer days for a seasonal pool.
Peak/off-peak schedule impact on yearly savings: The difference between the time-of-use savings estimate and the flat-rate savings estimate.
Common mistakes and quick fixes
Mistake: Entering horsepower in Current pump power instead of watts.
Fix: Use Current pump power in W from the pump label, manual, or power meter; do not type 1.5 hp as 1.5 W.
Mistake: Using cents in Electricity price, such as 18, when the label is $ per kWh.
Fix: Enter Electricity price as dollars per kWh, so 18 cents becomes 0.18.
Mistake: Leaving only Peak electricity price filled while Off-peak electricity price or peak-hour fields are blank.
Fix: Fill Current pump hours during peak price, Variable-speed pump hours during peak price, Peak electricity price, and Off-peak electricity price, or clear all four for flat-rate math.
Mistake: Entering Current pump hours during peak price greater than Current pump run time.
Fix: Make Current pump hours during peak price less than or equal to Current pump run time.
Mistake: Setting Pump use to 365 for a pool that only runs part of the year.
Fix: Enter Pump use as the number of days the pump runs during your pool season.
Limitations & Key Assumptions / Boundary Conditions
- The estimate covers pump electricity only. It does not include the purchase price, installation cost, rebates, repair cost, filters, heaters, lights, or other pool equipment.
- The calculator uses the watts you enter. Real pump watts can change with speed, plumbing resistance, filter condition, and pump settings.
- Time-of-use math uses one peak price and one off-peak price for every pump-use day. It does not model weekends, holidays, seasonal rate changes, demand charges, taxes, or tiered rates.
- Variable-speed pump run time does not prove the pool has enough turnover, cleaning, skimming, or chemical mixing. Check your pool builder, equipment manual, or local code if circulation requirements matter.
- Average monthly electricity savings divides yearly savings by 12. It is not a month-by-month bill forecast, especially for seasonal pools.
- A negative Estimated yearly electricity savings is allowed. It means the entered variable-speed schedule costs more to run than the current schedule.
Methodology
Energy cost basis
The calculator converts pump power from watts to kilowatts by dividing by 1000, then multiplies by run time, electricity price, and pump-use days. This matches the standard idea that electricity use is power over time, measured in kWh [1].
flat_cost = (pump_watts / 1000) * hours_per_day * flat_rate * days_per_year
Flat-rate savings
For flat-rate math, the calculator computes Current pump yearly electricity cost and Variable-speed pump yearly electricity cost with the same Electricity price.
estimated_yearly_savings = current_yearly_cost - variable_speed_yearly_cost
estimated_monthly_savings = estimated_yearly_savings / 12
Peak and off-peak math
If all four time-of-use fields are filled, the calculator prices peak hours and off-peak hours separately. Off-peak hours are total daily pump hours minus peak daily pump hours.
tou_cost = days_per_year * (pump_watts / 1000) * ((peak_hours_per_day * peak_rate) + ((hours_per_day - peak_hours_per_day) * off_peak_rate))
The flat-rate savings comparison is still calculated in the background so the schedule effect can be shown.
tou_schedule_impact = estimated_yearly_savings_using_tou - flat_rate_yearly_savings
Mini example
Suppose Current pump power is 1500 W, Current pump run time is 6 hours per day, Variable-speed pump power is 400 W, Variable-speed pump run time is 10 hours per day, Electricity price is $0.16 per kWh, and Pump use is 365 days. The current pump cost is (1500 / 1000) * 6 * 0.16 * 365 = $525.60 per year. The variable-speed pump cost is (400 / 1000) * 10 * 0.16 * 365 = $233.60 per year. Estimated yearly electricity savings is $525.60 - $233.60 = $292.00 per year.
Calculation choices
The calculator does not force savings to be positive. If Variable-speed pump yearly electricity cost is higher than Current pump yearly electricity cost, Estimated yearly electricity savings is negative. If some time-of-use fields are filled but others are blank, the calculator should stop and ask for either all four time-of-use fields or none, instead of mixing flat-rate and time-of-use math.