Water Pump Energy Cost Calculator
Estimate water-pump input power, horsepower, daily and monthly electricity use and cost from flow, total head, efficiency and operating schedule.
Default project preview
$13.58
Input power
0.63 kW
Hydraulic power
0.38 kW
Daily electricity
2.51 kWh
Monthly electricity
75.4 kWh
Calculator
Build the material order
Your order will appear here
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 flow rate
Enter this project assumption in gpm. The current imperial default is 20 gpm.
Total dynamic head
Enter this project assumption in ft. The current imperial default is 100 ft.
Overall pump efficiency
Enter this project assumption in %. The current imperial default is 60 %. Minimum: 1. Maximum: 100.
Operating hours per day
Enter this project assumption in hours. The current imperial default is 4 hours. Minimum: 0.1. Maximum: 24.
Operating days per month
Enter this project assumption in days. The current imperial default is 30 days. Minimum: 1. Maximum: 31.
Electricity price
Enter this project assumption in per kWh. The current imperial default is 0.18 per kWh. Minimum: 0.
How to read the outputs
Input power
0.84 hp. Default preview: 0.63 kW.
Hydraulic power
power delivered to water. Default preview: 0.38 kW.
Daily electricity
entered runtime. Default preview: 2.51 kWh.
Monthly electricity
entered operating days. Default preview: 75.4 kWh.
Daily pumped volume
at entered flow and runtime. Default preview: 4,800 gal.
Daily energy cost
entered electricity rate. Default preview: $0.45.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Hydraulic power = water density × gravity × flow × total head. Input power divides hydraulic power by overall efficiency. Energy use multiplies input power by runtime.
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: July 30, 2026
Use the Water Pump Energy Cost Calculator to estimate a planning quantity from verified flow, head, efficiency, runtime 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 flow, head, efficiency, runtime 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 pump requiring 1.5 kW input and running 3 hours per day uses 4.5 kWh; at $0.18/kWh the daily electricity cost is about $0.81.
Purchasing and rounding
Use input power at the required flow and head, preferably from a pump curve or measured data. Compare alternatives at the same duty point rather than by motor nameplate horsepower alone.
Interpret the result
The estimate converts pump input power and runtime into energy cost. Efficiency and power can change across the pump curve, so variable operating points need separate scenarios.
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.
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Water Pump Energy Cost Calculator questions
Why does more head increase energy use?+
The pump must add more energy to each unit of water as total dynamic head rises.
Does throttling change cost?+
Yes. Throttling changes the operating point on the pump curve and may reduce flow without proportional energy savings.
Can a variable-speed pump save energy?+
Often, when flow demand varies, but savings depend on the system curve and control strategy.