Torque Calculator
Calculate torque (moment of force) from force, arm length and angle.
How to use the torque calculator
- Enter the force being applied, in newtons (N).
- Enter the distance from the pivot point to where the force acts (the arm length), in meters.
- Enter the angle between the force direction and the arm — 90° for a perpendicular force (most common).
- The torque updates automatically, in newton-meters (N·m).
What is torque?
Torque (also called moment of force) measures how much a force causes something to rotate around a pivot point. It depends not just on how large the force is, but also how far from the pivot point it acts, and at what angle. The formula is τ = F × r × sin(θ), where F is the force, r is the arm length, and θ is the angle between them.
Frequently asked questions
Why does the formula use the sine of the angle?
Because only the component of the force that's perpendicular to the arm actually contributes to rotation. The sine of the angle between the force and the arm gives exactly this perpendicular component.
What's a practical example of torque?
Tightening a bolt with a wrench is a classic example — the longer the wrench handle (greater arm length), the less force you need to achieve the same torque.
What's the difference between torque and force?
Force (measured in newtons) is a straightforward "push" or "pull" in a direction. Torque (measured in newton-meters) is the effect of a force acting at a distance from a pivot point, describing how much that force will rotate something.