Torque Calculator

What is Torque?

Torque (also called moment) is a measure of the rotational force applied to an object. It describes the tendency of a force to rotate an object around an axis or pivot point. Torque is calculated by multiplying the applied force by the perpendicular distance from the axis of rotation (lever arm). The SI unit is Newton-meter (N·m), while imperial units include pound-foot (lb·ft) and pound-inch (lb·in). Understanding torque is crucial in mechanical engineering, automotive work, construction, and physics.

How to Use the Torque Calculator

1. Select calculation mode: calculate torque from force, force from torque, or distance from torque
2. Enter the applied force in your preferred unit (N, kN, lb, kgf)
3. Enter the lever arm distance (perpendicular distance from pivot to force application)
4. Optionally adjust the angle if force is not perpendicular to the lever arm
5. Click Calculate to see the torque in multiple units
6. Results show torque in N·m, lb·ft, and lb·in for easy conversion

Torque Formulas

Common Torque Examples

Applications of Torque

• Automotive: Tightening bolts, lug nuts, engine components to specification
• Construction: Fastener installation, structural connections, anchor bolts
• Manufacturing: Assembly processes, quality control, torque specifications
• Bicycles: Proper tightening of components, preventing over-tightening
• Machinery: Motor selection, gear calculations, shaft design
• Physics: Understanding rotational dynamics, angular momentum
• Tool design: Wrench length, mechanical advantage calculations

Tips for Torque Applications

• Always use a torque wrench for critical fasteners - never estimate
• Torque specifications are typically for clean, dry threads unless noted otherwise
• Maximum torque occurs at 90° - angle reduces effective torque
• Longer wrench = more leverage = same torque with less force
• Over-torquing can strip threads or break fasteners
• Under-torquing can lead to loosening and joint failure
• Check manufacturer specifications for proper torque values

Torque Direction & Sign Convention

Torque is a vector quantity with both magnitude and direction. By convention, counterclockwise rotation is considered positive torque, while clockwise rotation is negative. The right-hand rule determines direction: point your right thumb along the axis of rotation, and your fingers curl in the direction of positive torque. In calculations, we typically work with torque magnitude, but direction becomes important when analyzing systems with multiple torques or rotational equilibrium.