Torque Calculator
Calculate the torque of a force about a pivot from the force, lever arm length and angle.
How it works
τ = F · r · sin θ
Torque is the twisting effect of a force about a pivot, and it depends not just on how hard you push but on how far from the axis and at what angle. A force applied at right angles to the lever arm is fully effective; the same force along the arm produces no turn at all. Longer wrenches give more torque for the same push — the physics of leverage.
Worked example
Pushing with 50 N at the end of a 0.3 m wrench, at 90° to the handle: τ = 50 × 0.3 × sin 90° = 15 N·m (about 11.1 lb·ft).
Sources: Torque — Wikipedia
Frequently asked questions
Why does the angle matter?
Only the component of force perpendicular to the lever arm creates a turn, and that is F·sin θ. At 90° the whole force turns the object; along the arm (0° or 180°) it contributes nothing.
How do I get more torque?
Apply the force farther from the pivot or push at a right angle to the arm. Doubling the lever arm doubles the torque for the same force — which is why a longer wrench loosens a stubborn bolt.
What are the units of torque?
The SI unit is the newton-metre (N·m). Note it is dimensionally the same as the joule but is never written that way, because torque and energy are physically different quantities.
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Educational estimate. Check the formula and units for your exact case.