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Wind Energy Calculators

Wind Power Calculator

Power available in the wind and what a turbine can extract, from rotor size and wind speed.

Enter values

The Betz limit is 59.3%; real turbines reach 35–45%

Results update as you type.

Result

Electrical output

798 W

In kilowatts
0.798
Power in the wind
2,216.7 W
Betz limit (maximum possible)
1,314.5 W
Swept area
7.069 m²
At double the wind speed
6,384.1 W
power scales with the cube of speed
Daily energy at this speed
19.152 kWh

About the Wind Power Calculator

The power in the wind rises with the cube of wind speed, which is why site selection matters far more than turbine size. The Betz limit caps how much of it any turbine can capture at 59.3%; real machines reach 35–45%. Enter your rotor diameter and wind speed to see both numbers.

Also known as: wind turbine power, wind energy calculator, betz limit calculator, turbine output.

How to use this calculator

  1. Enter rotor diameter, wind speed, power coefficient, air density and the other fields.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

P = ½ρAv³ × Cp × efficiency

Worked example

Using the values pre-filled in the calculator above:

  • Rotor diameter = 3 m
  • Wind speed = 8 m/s
  • Power coefficient = 40 %
  • Air density = 1.225 kg/m³
  • Generator and drivetrain efficiency = 90 %

the calculator returns:

  • Electrical output: 798 W
  • In kilowatts: 0.798
  • Power in the wind: 2,216.7 W
  • Betz limit (maximum possible): 1,314.5 W

Frequently asked questions

Why does doubling the wind speed give eight times the power?

Power depends on velocity cubed — 2³ = 8. That is why a windy site beats a bigger turbine on a calm one.

What is the Betz limit?

No turbine can extract more than 59.3% of the wind’s kinetic energy, because the air has to keep moving to leave the rotor.