Productive ToolboxTorque Calculator
Calculate torque instantly using force and distance. Supports Newtons, pounds-force, meters, feet, angle correction, and real-time results.
Torque Calculator
Enter force and lever arm distance to instantly calculate torque. Supports metric and imperial units with optional angle correction for non-perpendicular forces.
Torque Result
Settings & Actions
Enter Values
Enable if force is not perpendicular to lever arm
Press Esc to reset
Quick Presets
What is a Torque Calculator?
A Torque Calculator is a mechanical engineering tool that computes the rotational force — or moment of force — applied around a pivot point. Torque is the product of force and the perpendicular distance from the axis of rotation to the line of action of the force.
The standard formula is τ = F × r, where τ is torque, F is the applied force, and r is the lever arm length. When the force is not perpendicular to the lever arm, the formula extends to τ = F × r × sin(θ), where θ is the angle between the force vector and the lever arm.
This calculator supports both metric (N, kN, m, cm, mm) and imperial (lbf, ft, in) unit systems, automatically converting all inputs to SI units before computing. Results are displayed in Nm, kNm, lb-ft, lb-in, and oz-in simultaneously.
How to Use the Torque Calculator
Step-by-Step Guide
- 1Enter the force magnitude (e.g. 100)
- 2Select the force unit — Newton, Kilonewton, or Pound-force
- 3Enter the lever arm distance (e.g. 1)
- 4Select the distance unit — mm, cm, m, in, or ft
- 5Optionally enable angle correction and set the angle θ
- 6View the torque result instantly in all units
Key Features
- ✓Real-time calculation as you type
- ✓Multi-unit support — metric and imperial
- ✓Angle correction toggle for non-perpendicular forces
- ✓Live formula display with your actual values
- ✓Unit conversion breakdown table (Nm, kNm, lb-ft, lb-in, oz-in)
- ✓Calculation history with localStorage persistence
- ✓Export results as a TXT file
- ✓Quick presets for common engineering scenarios
Torque Formula Explained
Perpendicular Force (θ = 90°)
When force is applied perpendicular to the lever arm, sin(90°) = 1, so the formula simplifies to the product of force and distance. This gives maximum torque for a given force and distance.
Angled Force (θ ≠ 90°)
When force is applied at an angle, only the perpendicular component contributes to rotation. At θ = 0° or 180°, torque is zero. At θ = 90°, torque is maximum.
Example Calculations
| Force | Distance | Angle | Torque |
|---|---|---|---|
| 50 N | 2 m | 90° | 100 Nm |
| 25 lbf | 3 ft | 90° | 75 lb-ft |
| 100 N | 0.5 m | 90° | 50 Nm |
| 80 N | 2 m | 45° | 113.14 Nm |
| 200 N | 30 cm | 90° | 60 Nm |
| 10 kN | 1.5 m | 90° | 15,000 Nm |
Nm vs lb-ft: Unit Conversion Reference
| Nm | kNm | lb-ft | lb-in |
|---|---|---|---|
| 1 | 0.001 | 0.7376 | 8.851 |
| 10 | 0.01 | 7.376 | 88.51 |
| 100 | 0.1 | 73.76 | 885.1 |
| 1,000 | 1 | 737.6 | 8,851 |
| 1 lb-ft = 1.356 Nm | |||
Real-World Applications of Torque
Bolt Tightening
Torque wrenches ensure bolts are tightened to exact specifications to prevent loosening or stripping.
Automotive
Engine torque determines acceleration. Wheel torque specs prevent over-tightening lug nuts.
Robotics
Servo motors are rated in oz-in or Nm. Torque calculations ensure joints can handle required loads.
Gear Systems
Gear ratios amplify or reduce torque. Understanding input torque is essential for gear design.
Structural Engineering
Moment calculations in beams and columns rely on the same torque principles.
Physics Education
Torque is a fundamental concept in rotational mechanics, taught in high school and university physics.
Frequently Asked Questions
What is torque?
Torque is the rotational equivalent of linear force. It measures how much a force causes an object to rotate around an axis. The SI unit is Newton-meter (Nm), and the US customary unit is pound-foot (lb-ft).
What is the torque formula?
For perpendicular force: τ = F × r. For angled force: τ = F × r × sin(θ). Where τ is torque, F is force, r is the lever arm distance, and θ is the angle between the force and lever arm.
When should I use angle correction?
Enable angle correction when the applied force is not perpendicular (90°) to the lever arm. For example, if you push a wrench at a 45° angle instead of straight down, the effective torque is reduced by sin(45°) ≈ 0.707.
What is the difference between Nm and lb-ft?
Both measure torque but in different unit systems. 1 lb-ft = 1.35582 Nm. Nm is the SI standard used globally in engineering, while lb-ft is common in the United States for automotive and mechanical applications.
Is this calculator accurate for engineering use?
Yes. The calculator uses exact conversion factors and IEEE 754 double-precision floating-point arithmetic. Results are accurate to the selected decimal precision. For critical applications, always verify with a licensed engineer.
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