Wind Turbine Torque Calculator
Calculate wind turbine shaft torque in N·m and lb-ft from power and RPM, reverse-calculate power from torque, or estimate rotor torque from wind speed, diameter, Cp and TSR.
🌬️ Field Rule: Torque and RPM together define mechanical power. Low rotor RPM can create high shaft torque, while the generator side often runs faster with lower torque through a gearbox. Use this with the Wind Turbine RPM Calculator, Tip Speed Ratio Calculator, Swept Area Calculator and Wind Turbine Power Calculator.
⚙️ Power + RPM → Rotor Torque → Gearbox / Generator Torque
Power
Rotor RPM
Power Location
Gearbox Ratio
Gearbox / Generator Efficiency
Show Main Result
Use this when you know turbine shaft power or electrical output and rotor RPM. For electrical output power, the calculator estimates the higher mechanical shaft torque before losses.
Presets:100W micro500W small1kW home3kW rural10kW farm
Torque
RPM
Efficiency
Gearbox Ratio Optional
Torque Side
Main Output
Use this to convert a known shaft torque and speed into mechanical power. This is useful for generator matching and gearbox comparisons.
Torque presets:10 N·m50 N·m100 N·m500 N·m
Rotor Diameter
Wind Speed
Tip Speed Ratio
Power Coefficient Cp
Electrical Efficiency
Air Density
This mode estimates rotor torque from wind power. Real torque changes with power curve, pitch, stall, generator load and cut-in speed.
Wind presets:1m / 6m/s3m / 6m/s5m / 8m/s10m / 9m/s
📐 Formula Reference
Torque from Power
T = P ÷ ω
Shortcut Formula
T(N·m) = 9550 × kW ÷ RPM
Power from Torque
P(W) = T(N·m) × 2π × RPM ÷ 60
Wind Rotor Torque
Pwind = 0.5ρAv³, then T = Pshaft ÷ ω
📋 Quick Reference
Power + RPM Example
1kW at 100rpm95.5 N·m
1kW at 200rpm47.8 N·m
5kW at 150rpm318 N·m
Unit Conversion
1 N·m0.7376 lb-ft
1 lb-ft1.3558 N·m
1 HP746 W
Design Meaning
Low RPMhigh torque
High RPMlower torque
Gearbox upRPM ↑ torque ↓
📚 Engineering Notes
Torque is shaft twisting forceIn a wind turbine, rotor torque is the twisting force delivered by the hub/shaft. Power depends on both torque and rotational speed.
Gearboxes trade torque for speedA step-up gearbox increases generator RPM but reduces generator-side torque roughly by the gear ratio after losses.
Large rotors can produce high torqueMore swept area captures more wind power. Compare with the Swept Area Calculator.
TSR controls RPM estimateWhen estimating from wind speed, TSR links blade tip speed, wind speed and rotor RPM. Use the TSR Calculator for blade design checks.
What is a Wind Turbine Torque Calculator?
A wind turbine torque calculator estimates the twisting force on the turbine shaft. It can calculate torque from power and RPM, calculate power from torque and RPM, or estimate rotor torque from wind speed, rotor diameter, Cp and TSR.
Torque vs power in a wind turbine
Torque is the shaft twisting force, while power is the rate of energy transfer. A slow rotor can have high torque, but power also depends on RPM. This is why P = T × ω is important for turbine and generator matching.
How gearbox ratio affects torque
A wind turbine gearbox usually increases generator RPM. When RPM increases, torque decreases in proportion to the gear ratio, minus mechanical and electrical losses. Rotor-side torque is usually much higher than generator-side torque.
Important limitation
This calculator gives engineering estimates. Real turbine torque depends on the turbine power curve, generator loading, blade pitch, stall behavior, cut-in speed, yaw error, turbulence, braking system and mechanical losses.
❓ Frequently Asked Questions
Use Torque N·m = 9550 × power kW ÷ RPM. For example, 1kW at 100rpm gives about 95.5 N·m.
Wind turbine torque is the twisting force produced at the rotor shaft by the blades. It is what turns the shaft, gearbox and generator.
Most large wind turbine rotors are low-RPM, high-torque machines. The generator may run at a higher RPM through a gearbox, or use direct-drive design with a large low-speed generator.
A step-up gearbox increases RPM and reduces torque on the generator side. It does not create extra power; it trades high rotor torque at low speed for lower generator torque at higher speed.
Generally yes, a longer blade increases swept area and captures more wind power, which can increase available rotor torque. Structural loading also rises, so blade and shaft design must be checked.
Starting torque is the torque needed to overcome generator cogging, bearing friction and load before the turbine begins rotating. Low starting torque is important for small wind turbines in light wind.
For the same power, torque and RPM are inversely related. If power is constant and RPM is lower, torque must be higher because P = T × ω.