Wind Turbine Power Calculator

Work out wind turbine power instantly with clear inputs, formula shown and shareable results.

About Wind Turbine Power Calculator

Wind power is half rho A v cubed. Two consequences dominate: doubling the rotor diameter quadruples power, and doubling wind speed multiplies it by eight. No turbine can exceed the Betz limit of 59.3% of the wind's power, and real machines reach 35-45%.

Formula

Wind power

P = 0.5 x rho x A x v^3 x Cp x efficiency; Betz limit Cp = 0.593

Worked example

With the default values below, Wind Turbine Power Calculator returns Electrical power output of 898. Change any input above and every figure here is recalculated in your browser.

Inputs used

Rotor diameter: 3.5 m
Wind speed: 8 m/s
Power coefficient: 0.35
Generator and converter efficiency: 85 %

Results

Electrical power output: 898 W
Swept area: 9.62 m²
Power in the wind: 3,017 W
Betz limit power: 1,788 W

Step by step

1Values used
2Wind power
3Electrical power output= 898 W
4Swept area= 9.62 m²
5Power in the wind= 3,017 W
6Betz limit power= 1,788 W

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why is site wind speed so critical?

Because power scales with the cube of speed. A site with 20% more wind yields about 73% more energy from the same turbine.

What is the Betz limit?

The theoretical maximum fraction of wind power any rotor can extract, 16/27 or 59.3%, since the air must retain some velocity to leave the rotor.