Pump Power Calculator
Fill in the values and the answer updates as you type.
How the Pump Power Calculator works
Hydraulic power (kW) = 9.81 × flow (L/s) × head (m) ÷ 1000 for water. Shaft power = hydraulic power ÷ pump efficiency. Motor losses come on top, so choose a motor somewhat larger than the shaft power. Head includes lift plus friction losses in the pipes. Example: with the default values, shaft power needed comes to 1.51 kW.
Inputs and results
The Pump Power Calculator takes 4 inputs and gives 4 results.
What you enter
- Flow rate (L/s) — starts at 5.
- Total head (m) — starts at 20.
- Pump efficiency (%) — starts at 65.
- Electricity price ($/kWh) — starts at 0.15.
What you get
- Shaft power needed (kW)
- Hydraulic power (kW)
- Shaft power (hp)
- Energy cost per hour
Example: Pump Power Calculator with the starting values
With flow rate 5 L/s, total head 20 m, pump efficiency 65 % and electricity price 0.15 $/kWh, the calculator returns:
| Shaft power needed (kW) | 1.51 |
|---|---|
| Hydraulic power (kW) | 0.98 |
| Shaft power (hp) | 2.02 |
| Energy cost per hour | $0.23 |
Change any value above and the results update straight away.
Pump Power Calculator FAQ
How do I use the Pump Power Calculator?
Enter flow rate, total head, pump efficiency and electricity price in the fields, then read shaft power needed (kw), hydraulic power (kw), shaft power (hp) and energy cost per hour in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Pump Power Calculator calculate?
Hydraulic and shaft power needed to pump water. It returns shaft power needed (kw), hydraulic power (kw), shaft power (hp) and energy cost per hour from the 4 values you provide.
What values does the Pump Power Calculator start with?
It opens with flow rate 5 L/s, total head 20 m, pump efficiency 65 % and electricity price 0.15 $/kWh so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Pump Power Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Pump Power Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.