Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Single unconstrained operating point. A real power curve includes cut-in, rated-power capping and cut-out; no annual yield is predicted.
Example Calculation
- Rotor diameter: 4 m
- Wind speed: 8 m/s
- Air density: 1.225 kg/m³
- Power coefficient Cp: 0.4
- Generator efficiency: 90 %
Diameter 4 m, wind 8 m/s, density 1.225, Cp 0.4 and generator efficiency 90% give about 1.419 kW.
Method references
Frequently asked questions
How do I use this calculator?
Enter rotor diameter, wind speed, air density, power coefficient cp, generator efficiency. The result updates automatically. Use Reset to restore the example values.
What method does it use?
electrical power=½ρ × πD²/4 × wind³ × Cp × generator efficiency.. Single unconstrained operating point. A real power curve includes cut-in, rated-power capping and cut-out; no annual yield is predicted.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.