Torque Calculator

Calculate torque from force and distance, find rotational power, or convert between torque units. Supports lever arm, angular acceleration, and power-speed-torque calculations.

How It Works

What is Torque?

Torque (also called moment of force) is a measure of the rotational force applied to an object. It describes how much a force acting on an object causes that object to rotate about an axis. The SI unit of torque is the newton-meter (N·m).

Key Formulas

• τ = F × r × sin(θ) — torque from force, lever arm distance, and angle
• τ = I × α — torque from moment of inertia and angular acceleration (Newton's second law for rotation)
• P = τ × ω — power equals torque times angular velocity
• ω = 2πn / 60 — convert RPM (n) to angular velocity in rad/s
• τ = P / ω = (60 × P) / (2π × n) — torque from power and RPM

Common Torque Units

Practical Examples

• Tightening a bolt with a 0.3 m wrench using 50 N of force produces 15 N·m of torque
• A car engine producing 200 hp at 5000 RPM generates about 284 N·m of torque
• Electric motors often deliver maximum torque at zero RPM, making them ideal for high-starting-load applications
• A torque wrench set to 100 N·m ensures bolts are tightened to specification without over-tightening

Torque vs. Power

Torque and power are related but distinct quantities. Torque measures the rotational force at an instant, while power measures the rate of doing work. A diesel engine may produce high torque at low RPM (strong pulling force), while a sports car engine may produce high power at high RPM (high top speed). The relationship P = τ × ω ties them together: power equals torque multiplied by angular velocity.

Related Utils

• Gear Ratio Calculator — calculate gear ratios, speed, and torque for gear trains
• Force Calculator (F=ma) — calculate force, mass, or acceleration
• Work & Power Calculator — calculate mechanical work and power
• Momentum Calculator — linear and angular momentum
• Unit Converter — convert between engineering units