Torque Converter

Torque (τ) is the turning effect of a force: the force times its distance from the axis, τ = F * r, when the force is at right angles to the lever. Its SI unit is the newton meter (N·m). In the US, torque is given in pound-feet (lb-ft, lbf·ft) for engines and wheel nuts, and in pound-inches (in-lb) for small fasteners.

A 100 N push on the end of a 0.3 m spanner gives 100 * 0.3 = 30 N·m.

How to convert torque units

Type a value into any field, and every other unit is calculated at once. For example, an engine making 550 N·m:

1. In lb-ft: multiply by 0.737562.

   550 * 0.737562 = 405.7 lbf·ft

2. In kgf·m: divide by 9.80665.

   550 / 9.80665 = 56.08 kgf·m

Common conversions

Torque units

• Newton meter (N•m): The newton meter is the standard unit of torque in the International System of Units (SI). It represents the torque produced when a force of one newton is applied at a distance of one meter from the axis of rotation.

• Kilonewton meter (kN•m): The kilonewton meter is a unit of torque in the metric system. One kilonewton meter (kN•m) is equal to 1,000 newton meters.
  Conversion Factor: 1 kN•m = 1,000 N•m

• Millinewton meter (mN•m): The millinewton meter is a small unit of torque, where one millinewton meter (mN•m) is equal to one-thousandth (1/1000) of a newton meter.
  Conversion Factor: 1 mN•m = 0.001 N•m

• Dyne meter (dyn•m): The dyne meter combines the CGS unit of force, the dyne, with the meter. It is the torque produced when a force of one dyne is applied at a distance of one meter from the axis of rotation.
  Conversion Factor: 1 dyn•m = 0.00001 N•m

• Kilogram-force meter (kgf•m): The kilogram-force meter is a unit of torque derived from the gravitational force exerted on a mass of one kilogram. It represents the torque produced when a force of one kilogram-force is applied at a distance of one meter from the axis of rotation.
  Conversion Factor: 1 kgf•m = 9.80665 N•m

• Gram-force meter (gf•m): The gram-force meter is a unit of torque derived from the gravitational force exerted on a mass of one gram. It represents the torque produced when a force of one gram-force is applied at a distance of one meter from the axis of rotation.
  Conversion Factor = 1 gf•m = 0.001 kgf•m = 0.00980665 N•m

• Pound-force foot (lbf•ft): The pound-force foot is a unit of torque commonly used in the United States. It represents the torque produced when a force of one pound-force is applied at a distance of one foot from the axis of rotation.
  Conversion Factor: 1 lbf•ft = 1.3558 N•m

• Pound-force inch (lbf•in): The pound-force inch is another unit of torque commonly used in the United States. It represents the torque produced when a force of one pound-force is applied at a distance of one inch from the axis of rotation.
  Conversion Factor: 1 lbf•in = 1/12 lbf•ft = 0.113 N•m

• Ounce-force foot (ozf•ft): The ounce-force foot is a unit of torque used primarily in the United States that represents the torque produced when a force of one ounce-force is applied at a distance of one foot from the axis of rotation.
  Conversion Factor: 1 ozf•ft = 1/16 lbf•ft = 0.0847 N•m

• Ounce-force inch (ozf•in): The ounce-force inch is a unit of torque used in the United States that represents the torque produced when a force of one ounce-force is applied at a distance of one inch from the axis of rotation.
  Conversion Factor: 1 ozf•in = 1/12 ozf•ft = 0.00706 N•m

• Poundal foot (pdl•ft): The poundal foot is a unit of torque in the foot-pound-second (FPS) system. It represents the torque produced when a force of one poundal is applied at a distance of one foot from the axis of rotation.
  Conversion Factor: 1 pdl•ft = 1/32.1741 lbf•ft = 0.04214 N•m

• Poundal inch (pdl•in): The poundal inch is a unit of torque in the foot-pound-second (FPS) system. It represents the torque produced when a force of one poundal is applied at a distance of one inch from the axis of rotation.
  Conversion Factor: 1 pdl•in = 1/12 pdl•ft = 0.00351 N•m

Frequently asked questions

Is lb-ft the same as ft-lb?

For torque, yes: both mean a pound-force at a distance of one foot. Engineers often write lb-ft for torque and ft-lb for work and energy, which have the same units, to keep the two apart.

What torque do car wheel nuts need?

Typically 80–140 N·m (60–100 lb-ft) for cars, depending on the make. The vehicle's handbook gives the exact value.