Torque Calculator
Calculate torque (τ = F × d), force, or lever arm length. Essential for mechanical engineering, automotive maintenance, and physics coursework.
As an Amazon Associate and CJ Affiliate publisher we earn from qualifying purchases. Prices and availability may vary.
Torque Guide
What do I need to know about Torque Formula?
Torque (τ) = Force (F) × perpendicular distance (d) × sin(θ), where θ is the angle between the force vector and the lever arm. When force is applied at 90° (perpendicular), sin(90°) = 1 and τ = F × d. Torque is measured in Newton-metres (N⋅m) in SI units, or foot-pounds (ft⋅lb) in imperial. 1 N⋅m = 0.7376 ft⋅lb. Torque is a vector quantity — the direction (clockwise or anticlockwise) matters for equilibrium problems.
What's the key thing to understand about Common Torque Values?
Tightening bolts: M6 bolt ~10 N⋅m, M10 bolt ~45 N⋅m, M14 bolt ~120 N⋅m, car wheel nuts 80–130 N⋅m. Bicycle components: stem bolts 4–6 N⋅m, bottom bracket 35–50 N⋅m. Car engine output: a 1.0 litre petrol engine ~150 N⋅m, 2.0 litre diesel ~350 N⋅m, performance V8 ~700+ N⋅m. Electric motors can deliver full torque from standstill — a Tesla Model S produces ~660 N⋅m instantly. A human hand grip applies approximately 3–5 N⋅m on a standard screwdriver.
What should I know about Torque Wrenches?
A torque wrench ensures bolts are tightened to a specific torque, preventing over-tightening (which can strip threads or warp components) or under-tightening (which can cause fasteners to loosen). Critical applications: cylinder head bolts (often tightened in multiple stages), wheel nuts (critical for road safety), suspension components, and brake caliper bolts. Most torque wrenches specify the bolt torque in N⋅m; car manufacturer specifications are given in the service manual.
What do I need to know about Torque and Power?
Power (W) = Torque (N⋅m) × Angular velocity (rad/s). Angular velocity in rad/s = RPM × 2π/60. So Power (kW) = Torque × RPM / 9549. An engine producing 200 N⋅m at 3000 RPM generates: 200 × 3000 / 9549 = 62.8 kW (84 hp). This is why car manufacturers specify torque at a particular RPM rather than just giving a single number — torque varies across the rev range, peaking at different RPMs for petrol vs diesel engines.