Physics

Torque Calculator

Torque from force and lever arm length.

Enter your values

Enter the force in N.

Enter the lever arm length in m.

Enter the angle to lever arm in degrees.

Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.

Results
Torque
28 N·m
Torque
20.65 ft·lb

Quick answer

Torque = F x r x sin(theta).

tau = F r sin(theta)

At a glance

What it doesTorque from force and lever arm length.
CategoryPhysics
Inputs neededForce, Lever arm length, Angle to lever arm
Main outputTorque
Formulatau = F r sin(theta)
CostFree — no sign-up, no download

How to use the Torque Calculator

  1. 1Enter the applied force and the length of the lever arm.
  2. 2Enter the angle between the force and the lever arm (90 degrees is most effective).
  3. 3Read the resulting torque.

Inputs explained

Force(N)
Enter the force in N.
Lever arm length(m)
Enter the lever arm length in m.
Angle to lever arm(degrees)
Enter the angle to lever arm in degrees.

Worked example

Using the values the calculator loads with:

Inputs

  • Force80 N
  • Lever arm length0.35 m
  • Angle to lever arm90 degrees

Results

  • Torque28 N·m
  • Torque20.65 ft·lb

Frequently asked questions

Why is angle 90 degrees usually used?

Torque is maximised when the force is perpendicular to the lever arm.

How does this relate to a wrench?

A longer wrench (bigger lever arm) produces more torque for the same hand force.

What do I need to enter into the Torque Calculator?

Just 3 values: force, lever arm length, angle to lever arm. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.

How does the Torque Calculator work out the answer?

Torque = F x r x sin(theta). It applies the formula tau = F r sin(theta) and shows the working so you can check each step by hand.

Is the Torque Calculator free, and do I need an account?

It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.

Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.