Torque calculator
Enter the arm length from the pivot to where the force acts, the force and the angle between them. 90 degrees gives the most torque.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter lever arm length, force and angle between arm and force.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
τ = r × F × sin θ. One lbf·ft = 1.35582 N·m and one kgf·m = 9.80665 N·m.
Example
Inputs: Lever arm length = 0.3 m, Force = 100 N, Angle between arm and force = 90 degrees. Result: Torque: 30 N·m; In pound-force feet: 22.1269 lbf·ft; In kilogram-force meters: 3.0591 kgf·m.
Limits and caveats
- Gives the size of the torque only, not the turning direction.
- Assumes a single constant force; add up torques yourself when several forces act.
Questions about this tool
Why does a longer wrench make a nut easier to undo?
Torque is force times arm length, so doubling the wrench length gives the same torque with half the force.
Why is torque in N·m and not joules?
They share dimensions, but torque is written N·m and not called joules because it is not work done.
How do I convert engine torque from lb·ft to N·m?
Multiply by about 1.35582. For example, 300 lb·ft is about 406.7 N·m.