Torque Calculator
Calculate torque from an applied force and lever arm, or from transmitted power and rotational speed.
Enter your values
Choose mode, then fill in the fields below.
How this calculator works
Torque from a force applied at a distance from a pivot is simply the product of force and lever arm (moment arm), when the force is perpendicular to the arm:
F is the applied force and r is the perpendicular distance from the pivot to where the force acts. When torque is transmitted through a rotating shaft at known power and speed:
P is power in watts, N is speed in RPM. Both modes return torque in N·m.
Unit conversion reference
| From | To | Multiply by |
|---|---|---|
| N·m | lb·ft | 0.7376 |
| N·m | lb·in | 8.851 |
| kgf·m | N·m | 9.807 |
Frequently asked questions
What if the force isn't perpendicular to the lever arm?
Multiply by the sine of the angle between the force and the lever arm: T = F·r·sin(θ). At 90° (perpendicular), sin(θ) = 1 and the formula reduces to T = F·r.
Is this the same torque used for bolt tightening?
The underlying physics is the same (force × distance), but bolt tightening torque also accounts for thread and bearing friction — use the dedicated bolt torque calculator for that case.