About the Hydropower Calculator
Power from a micro-hydro scheme using head, flow rate and turbine efficiency.
Also known as: micro hydro calculator, water power calculator, hydroelectric output, water turbine power.
How to use this calculator
- Enter net head, flow rate, system efficiency, operating hours per year and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
P = ρ g Q H × efficiency
Worked example
Using the values pre-filled in the calculator above:
- Net head = 20 m
- Flow rate = 50 L/s
- System efficiency = 70 %
- Operating hours per year = 8,000
- Value per kWh = 0.2
the calculator returns:
- Power output: 6,864.7 W
- In kilowatts: 6.8647
- Annual energy: 54,917 kWh
- Theoretical power: 9,806.7 W