Wind Power Density Calculator
Wind power density measures the theoretical power available per square meter of area swept by the wind — the fundamental starting point for wind resource assessment, independent of any specific turbine design. This calculator takes your wind speed and air density and reports power density in W/m2 using the cubic power law. Because power scales with the cube of wind speed, even modest speed differences matter enormously for site selection. Pair the result with our Wind Turbine Output Calculator to convert power density into actual turbine output, and our Capacity Factor vs. Hub Height Calculator to see how raising hub height lifts the wind speed that drives this number.
The average wind speed at the site, typically measured at hub height or extrapolated to it. Higher wind speed has a cubic effect on power density.
1.225 kg/m3 is standard sea-level air density at 15C. Air density decreases with altitude and increases at lower temperatures -- adjust for high-elevation or unusual climate sites.
0.5 × air density (kg/m3) × wind speed (m/s)^3
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →Wind power density scales with the cube of wind speed, not linearly -- which is why even modest wind speed differences matter enormously for site selection. A location averaging 7 m/s has roughly 210 W/m2 of power density, but bump that average to just 8 m/s and density jumps to nearly 314 W/m2, a 49% increase from a wind speed gain of only 14%. This cubic relationship is the single most important reason wind resource assessment -- and hub height, which increases average wind speed -- matters so much to project economics.
How wind power density is calculated
This calculator estimates the theoretical power available per square meter of area swept by the wind, tying two inputs together: the wind speed and the air density. One quantity ties the calculation together.
Wind Power Density (W/m2) = 0.5 × Air Density (kg/m3) × Wind Speed (m/s)^3. The power available in moving air comes from its kinetic energy flux: the mass of air moving through a given area per unit of time (proportional to wind speed) multiplied by the kinetic energy per unit of mass (proportional to wind speed squared). Combining these gives a cubic relationship -- power scales with the cube of wind speed. Air density sets the mass term: higher density means more mass of air moving at a given speed, directly increasing power density. At the defaults (7 m/s, 1.225 kg/m3), that is 0.5 × 1.225 × 7^3 = 0.5 × 1.225 × 343 = 210.1 W/m2.
Two notes on the model. First, wind power density is a theoretical measure of the power available in the wind resource itself -- it is not the actual electrical output of a turbine. Real turbine output also depends on the rotor swept area and the turbine's power coefficient (efficiency), which by Betz's law can never exceed 59.3% of the available power, and in practice lands around 35-45% for modern utility-scale turbines. Second, air density varies with altitude and temperature: it decreases roughly 10-12% per 1,000m of elevation gain and increases in colder temperatures, which is why the same wind speed yields different power output at a high-elevation site versus a sea-level site. Data sources: wind power density formula from wind physics and kinetic energy principles (IEC 61400 wind turbine design standards); air density at sea level and altitude from atmospheric physics and meteorological standards; wind power classification bands from NREL wind resource assessment methodology and utility-scale wind project site evaluation; power coefficient and rotor swept area data from turbine design standards and manufacturer specifications. Verification: with defaults (7 m/s, 1.225 kg/m3), Wind Power Density = 210.1 W/m2.