What Is a Torque Calculator?
A torque calculator finds the rotational force (torque) produced when a force is applied at a distance from a pivot point. Torque is what turns wrenches, spins engines, and rotates anything around an axis. Enter the force, the lever arm length, and the angle of application, and the calculator returns the torque — or rearranges the equation to solve for force or distance.
How to Use the Calculator
- Enter the force applied.
- Enter the lever arm length — the distance from the pivot to where the force acts.
- Enter the angle between the force and the lever arm (90° for maximum torque).
- Calculate — see the torque.
The Torque Formula
τ = F × r × sin(θ)
where τ is torque, F is force, r is the lever arm length, and θ is the angle between them. When the force is perpendicular to the lever arm (θ = 90°), sin(θ) = 1 and torque is simply F × r — the maximum for that force and distance.
Units of Torque
| System | Unit |
|---|---|
| SI (metric) | Newton-meter (N·m) |
| Imperial | Pound-foot (lb·ft) |
| Conversion | 1 lb·ft ≈ 1.356 N·m |
Why Angle Matters
Torque is greatest when force is applied at 90° to the lever arm. Push at a shallower angle and only the perpendicular component contributes, reducing torque. This is why you push a wrench straight across, not along its length, to loosen a bolt.
Where Torque Is Used
- Automotive: engine output and tightening bolts to spec.
- Mechanics: wrenches, gears, and machinery.
- Physics: rotational dynamics and equilibrium.
- Construction: fasteners torqued to required values.
Frequently Asked Questions
What is the torque formula?
Torque equals force times lever arm length times the sine of the angle between them: τ = F × r × sin(θ). At 90°, it simplifies to F × r.
What units is torque measured in?
Torque is measured in newton-meters (N·m) in SI units and pound-feet (lb·ft) in imperial units. One pound-foot is about 1.356 newton-meters.
Why does a longer wrench make loosening easier?
A longer lever arm increases the distance r, so the same force produces more torque. That is why a longer wrench loosens stubborn bolts more easily.
At what angle is torque maximum?
Torque is greatest when the force is applied perpendicular (90°) to the lever arm, because sin(90°) equals 1.
Is this torque calculator free?
Yes — it is completely free, requires no signup, and solves for torque, force, or distance.