Physics

Torque Calculator

Calculate torque from force and lever-arm distance.


Torque Calculator

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Torque is a rotational force — this calculates it from a linear force applied at a distance from a pivot point.

How it works

Force is multiplied by the lever-arm distance from the pivot to give torque, assuming the force is applied perpendicular to the lever arm.

What this does not include

This does not include converting torque into horsepower at a given rotational speed — for that, use this site’s torque to horsepower calculator instead.

How to use this calculator

  1. Enter the force applied and the distance from the pivot point.

A worked example

A 50 N force applied at a 0.3 m lever arm: torque = force × distance = 50 × 0.3 = 15 N·m.

A 100 N force at 0.5 m: torque = 50 N·m.

What the variables mean

Variable Meaning
Force Applied force, perpendicular to the lever arm
Distance Lever arm length — distance from the pivot to where force is applied

Edge cases worth knowing

Torque scales with the lever arm, not just the applied force. A wrench extension lets a smaller force produce the same torque as a larger force on a shorter handle — the entire reason longer wrenches make bolts easier to turn.

A distance of zero produces zero torque regardless of force — a force applied exactly at the pivot point has no leverage to rotate anything.

Frequently asked questions

What’s a real-world example of torque?

Turning a wrench — the same force produces more torque (and loosens a bolt more easily) the farther out on the handle it’s applied.

What happens if the force isn’t perpendicular to the lever arm?

Only the perpendicular component of the force contributes to torque — this calculator assumes a fully perpendicular force, the simplest and most common case.

What are the units of torque?

Newton-meters (N·m) in SI units — the same units as energy, though torque and energy are conceptually different quantities.

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Written by

R. Solano

Physics writer

R. Solano writes the physics calculators, spanning mechanics, electricity, optics and thermodynamics. Each page names the physical model it uses and the conditions under which that model holds — ideal gas, no air resistance, small-angle approximation — because a physics result without its assumptions is a number without a meaning. Formulas are given in symbols first, then in the calculator.

Reviewed by

V. Kowalski

Calculator reviewer — physics and engineering

V. Kowalski reviews the physics and engineering calculators, checking that each page states the physical model it assumes and that the stated model matches the formula actually implemented. Review covers unit consistency throughout a calculation and whether approximations are flagged where the underlying physics is more complicated than the formula suggests.

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