Ecology & Environment

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Wind Turbine Calculator.

Calculate aerodynamic wind power from air density, rotor diameter, wind speed, and efficiency.

On-device calculationNo signup
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Set your values

Results update as you type.

Swept area: 1,963.495408 m²

Swept area

1,963.495408m²
Power: 246,300.864041 W

Power

246,300.864041W
Power: 246.300864 kW

Power

246.300864kW

Results update automatically as you type.

Use Cases

Estimate potential power for a small wind turbine

Use this calculator to get a rough idea of how much power a small wind turbine could generate at your site, based on rotor size and average wind speed.

Example: A 5 m diameter turbine with 40% efficiency in 6 m/s wind at sea level produces about 2.1 kW.

Compare turbine designs or locations

Adjust rotor diameter, wind speed, or efficiency to see how changes affect power output, helping you compare different turbine options or potential installation sites.

Example: Doubling wind speed increases power by a factor of 8, so a 10 m/s wind yields 8 times more power than 5 m/s.

Frequently Asked Questions

How is wind turbine power calculated?
The calculator uses the formula P = 0.5 * air density * swept area * wind speed^3 * efficiency. The swept area is derived from the rotor diameter (π * (diameter/2)^2). You input air density, rotor diameter, wind speed, and overall efficiency to get the power output in watts.
What is the typical air density value?
At sea level and 15°C, air density is about 1.225 kg/m³. It decreases with altitude and temperature. You can adjust this value based on your location and conditions for more accurate results.
What does 'overall efficiency' mean?
Overall efficiency accounts for losses in the turbine, generator, and other components. It is a fraction between 0 and 1. Real turbines typically have efficiencies between 0.3 and 0.5, with the Betz limit at 0.593.

Tips & Common Mistakes

Tips

  • Use the actual air density for your altitude and temperature for more accurate results. At higher altitudes, air density is lower, reducing power output.
  • Wind speed is the most critical factor because power increases with the cube of wind speed. Even a small increase in wind speed significantly boosts power.
  • Remember that the Betz limit (59.3%) is the theoretical maximum efficiency for a wind turbine. Realistic overall efficiency values are typically 30-50%.
  • Check the units: ensure rotor diameter is in meters, wind speed in meters per second, and air density in kg/m³ to get power in watts.

Common Mistakes to Avoid

  • Using wind speed in km/h or mph without converting to m/s. The calculator expects m/s, so convert first (1 m/s = 3.6 km/h).
  • Entering efficiency as a percentage (e.g., 40) instead of a fraction (0.4). The calculator expects a fraction between 0 and 1.
  • Forgetting that the rotor diameter is the full diameter, not the radius. The swept area is calculated from the diameter you provide.

Last updated: August 13, 2026