Betz Limit Calculator
Compute the maximum extractable wind power and the Betz efficiency.
Input Data
Air Density Kg Per M3
kg/m³
Rotor Area M2
m²
Wind Speed Ms
m/s
Power Coefficient
Results
P = ½ρA v³ Cp.
1,924,230W
Actual Cp used.
0.4
Cp / (16/27).
0.675
½ρA v³ · 16/27.
2,850,711.111111W
At a glance:P = ½ρ·A·v³·Cp; the Betz limit caps Cp at 16/27 ≈ 0.593. Complements wind energy and aerodynamics.
Formula
P = ½·ρ·A·v³·Cp.
Cp_max = 16/27.
$$P = \frac{1}{2} \rho A v^3 C_p, \quad C_{p,max} = \frac{16}{27} \approx 0.5926, \quad \eta = \frac{C_p}{C_{p,max}}$$How to Use
- Enter air density, rotor area, wind speed and Cp.
- The tool returns power and Betz efficiency.
Case Studies
ρ=1.2, A=10, v=10, Cp=0.4
P = 2400 W.
FAQ
Why 59.3%?
Maximum kinetic energy removable without stopping the flow (Betz 1919).
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.