Estimate your sump pump's daily energy use and pump-only electricity cost from its running watts, runtime, and electricity rate.
Table of contents
How to use our Sump Pump Electricity Cost Calculator
- Choose how you track pump run time: direct daily hours or observed pump cycles.
- Enter Pump running power from the pump label, manual, specification sheet, or an electricity monitor.
- Enter either Average pump run time or both Average pump cycles and Average run time for each cycle.
- Replace Electricity rate with the usage-dependent cents per kWh from your utility bill, then select Calculate.
- Check Calculated pump run time per day first. If it does not match what you observe, revise the runtime inputs before using the monthly or yearly cost.
Definitions
Running power (W): Electrical power the pump uses while it is running, measured in watts. This is different from motor horsepower.
kWh: Kilowatt-hour, a unit of electrical energy. A 1,000-watt device running for one hour uses 1 kWh.
Average pump cycles (per day): The average number of times the pump starts and runs in one day.
Average run time for each cycle (minutes): The average number of minutes the pump operates each time it starts.
Usage-dependent electricity rate: The cents per kWh charges that increase when you use more electricity. It does not include a fixed monthly customer charge.
Calculated pump run time per day: The total minutes of pumping used for the energy and cost estimate.
Common mistakes and quick fixes
Mistake: Entering motor horsepower in Pump running power.
Fix: Enter electrical running watts from the pump label, manual, or a suitable electricity monitor.
Mistake: Entering 30 for Average pump run time when the pump runs 30 minutes daily.
Fix: Enter 0.5 hours, or choose cycles and enter Average pump cycles plus Average run time for each cycle.
Mistake: Counting pump starts but guessing Average run time for each cycle.
Fix: Time several runs with a stopwatch and enter a reasonable average in minutes.
Mistake: Adding a fixed monthly customer charge to Electricity rate.
Fix: Enter only charges that change with kWh. Fixed charges are excluded from Estimated pump electricity cost per month.
Mistake: Treating one stormy day as the whole year.
Fix: Use a representative average and treat Estimated pump electricity cost per year as a planning estimate.
Mistake: Skipping Calculated pump run time per day.
Fix: Compare it with your observations before relying on the cost results.
Limitations & Key Assumptions / Boundary Conditions
- The estimate assumes the entered daily runtime represents all 365 days of the planning year. Rainfall, snowmelt, groundwater, and drainage conditions can change pump operation greatly.
- It uses one running-power value. Actual wattage can differ from a nameplate value because of pump load, voltage, and motor condition.
- Standby power while the pump is off is not included.
- The electricity rate is treated as one constant usage-dependent price. Time-of-use pricing, tiered prices, taxes, and changing delivery charges can make the actual cost differ.
- Fixed monthly utility customer charges are excluded because they normally do not change when the pump runs.
- A calculated daily runtime above one day is rejected. Check the cycle count and minutes per cycle if that happens.
Methodology
Calculation method
The calculator first finds total daily pumping time. It then converts watts to kilowatts, multiplies by operating hours, and applies the entered electricity rate.
daily runtime in minutes = hours per day x 60
daily runtime in minutes = cycles per day x minutes per cycle
daily energy in kWh = (running power in W / 1000) x daily runtime in hours
monthly energy in kWh = daily energy x 365 / 12
yearly energy in kWh = daily energy x 365
electricity cost = energy in kWh x electricity rate in cents per kWh / 100
Worked example
An 800 W pump running 0.5 hours per day uses 0.4 kWh per day: (800 / 1000) x 0.5. Over an average month, that is 12.1667 kWh. At 18.44 cents per kWh, the estimated monthly pump-only cost is $2.24.
Calculation choices
Monthly results use 365 days divided by 12, so they are average monthly values rather than a specific calendar month. The editable 18.44 cents per kWh default is a May 2026 US residential planning estimate. Replace it with the applicable usage-dependent rate from your bill. [1]