Well Pump Running Cost Calculator
Estimate well-pump electricity use and operating cost from motor size, load factor, daily runtime, flow rate and electricity price.
Default project preview
$10.74 per month
Estimated input power
0.8 kW
Monthly energy
59.7 kWh
Monthly water volume
45,000 gal
Cost per 1,000 volume
$0.24
Calculator
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Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Pump motor size
Enter this project assumption in hp. The current imperial default is 1 hp.
Average motor load
Enter this project assumption in %. The current imperial default is 80 %. Minimum: 1. Maximum: 100.
Motor and drive efficiency
Enter this project assumption in %. The current imperial default is 75 %. Minimum: 10. Maximum: 100.
Average runtime per day
Enter this project assumption in hr/day. The current imperial default is 2.5 hr/day.
Operating days per month
Enter this project assumption in days. The current imperial default is 30 days. Minimum: 1. Maximum: 31.
Average water flow
Enter this project assumption in gal/min. The current imperial default is 10 gal/min.
Electricity rate
Enter this project assumption in per kWh. The current imperial default is 0.18 per kWh. Minimum: 0.
How to read the outputs
Estimated input power
load and efficiency adjusted. Default preview: 0.8 kW.
Monthly energy
input power × runtime. Default preview: 59.7 kWh.
Monthly water volume
flow × runtime. Default preview: 45,000 gal.
Cost per 1,000 volume
per 1,000 gal. Default preview: $0.24.
Daily runtime
entered average. Default preview: 2.5 hr.
Annualized cost
monthly estimate × 12. Default preview: $128.86.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Estimated input kW = motor shaft power × load factor ÷ efficiency. Monthly energy = input kW × hours per day × days. Cost = kWh × electricity rate.
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 30, 2026
Use the Well Pump Running Cost Calculator to estimate a planning quantity from verified motor power, duty cycle and electricity tariff. It supports scope comparison, purchasing and operating-cost planning, but it does not select equipment, approve code compliance or replace project-specific design.
Calculation steps
- 1Measure or obtain each design input from the actual project and keep one consistent unit system.
- 2Enter motor power, duty cycle and electricity tariff using product data or approved design information rather than generic nominal values.
- 3Review the unrounded engineering or usage result before applying allowances, duty cycle, efficiency or tariff assumptions.
- 4Apply each adjustment once, then round only the final purchasing, equipment-count or scheduling output.
Worked numerical example
A 1.1 kW well pump accumulating 2 hours of runtime per day uses 2.2 kWh; at $0.19/kWh that is about $0.42 per day.
Purchasing and rounding
Use actual pump input power and accumulated runtime or a justified duty cycle. Pressure setting, drawdown and cycling affect runtime and should be addressed before comparing energy cost.
Interpret the result
The result is an electrical operating-cost estimate. It does not diagnose well yield or pressure-tank performance, and frequent cycling can increase starts without proportionally increasing useful water delivery.
Page-specific assumptions
- Inputs describe the actual connected system or measured project scope.
- One operating condition, product rating and unit system are used per calculation.
- Allowances and efficiency losses are not already embedded in the entered values.
- Code, health, structural, electrical and hydraulic requirements are verified independently.
Common mistakes
- Using nominal equipment ratings instead of delivered performance at design conditions.
- Mixing instantaneous flow or power with daily or annual energy.
- Applying the same allowance more than once.
- Treating a quantity or cost estimate as equipment selection or professional approval.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
Related tools
Continue planning the project
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Well Pump Running Cost Calculator questions
Why is electrical input higher than shaft power?+
Motors and drives are not perfectly efficient, so electrical input can exceed the mechanical output rating.
Does pump cycling affect cost?+
Yes. Frequent starts, pressure losses and short cycling can change actual runtime and efficiency.
Can measured wattage be used?+
The calculator does not have a direct measured-kW field, but you can choose metric mode and enter the measured input kW with load and efficiency both set to 100%.