Supported units
- Newton meter (N·m)
- Kilogram-force meter (kgf·m)
- Pound-force foot (lbf·ft)
- Pound-force inch (lbf·in)
Conversion tool
Torque Converter
Select a category, enter a value, and convert between compatible units.
Torque units explained
Torque describes the turning effect of a force acting at a distance from an axis. The SI unit is the newton metre, while pound-foot and kilogram-force metre are also widely used.
Common engineering uses
Torque conversion is important for motors, engines, shafts, gearboxes and fastener specifications. Torque should not be confused with energy, despite similar unit dimensions.
Formula
τ = F × r
Torque equals the force multiplied by the perpendicular distance from the axis of rotation to the force's line of action. The SI unit is the newton metre (N·m).
- τ = torque, measured in newton metres (N·m)
- F = applied force, measured in newtons (N)
- r = perpendicular lever arm, measured in metres (m)
Common conversions
| From | Equivalent value |
|---|---|
| 1 newton metre (N·m) | 0.737562 pound-foot (lb·ft) |
| 1 pound-foot (lb·ft) | 1.35582 newton metres (N·m) |
| 1 newton metre (N·m) | 8.85075 pound-inches (lb·in) |
| 1 kilogram-force metre (kgf·m) | 9.80665 newton metres (N·m) |
| 1 newton centimetre (N·cm) | 0.01 newton metre (N·m) |
Convert 120 N·m to lb·ft
- Use the relationship 1 N·m = 0.737562 lb·ft.
- Multiply 120 by 0.737562.
- 120 × 0.737562 = 88.5074 lb·ft.
120 N·m ≈ 88.51 lb·ft
This is a unit conversion only. A fastener's required torque must still be taken from the relevant engineering specification or manufacturer data.
Engineering applications
- Selecting motors and gearboxes for machinery and automation systems.
- Specifying tightening torque for bolts, nuts and other threaded fasteners.
- Comparing engine output and drivetrain specifications.
- Designing shafts, couplings, brakes and rotating equipment.
- Checking torque-wrench settings when specifications use different unit systems.
Common mistakes
- Confusing torque with energy. Both can be expressed using newton metres dimensionally, but they describe different physical quantities.
- Using the full lever length instead of the perpendicular distance to the force's line of action.
- Confusing pound-foot (lb·ft) with pound-inch (lb·in); the numerical values differ by a factor of 12.
- Treating kilogram-force as kilogram mass. A kgf is a unit of force, not mass.
- Applying a converted value without checking whether the specification also requires an angle-tightening stage.
Frequently asked questions
How many lb·ft are in one N·m?
One newton metre is approximately 0.737562 pound-foot.
How many N·m are in one lb·ft?
One pound-foot is approximately 1.35582 newton metres.
Are lb·ft and ft·lb the same torque unit?
They are often used interchangeably for torque, but lb·ft is the clearer convention because ft·lb is also commonly associated with energy.
Is torque the same as power?
No. Torque is a turning moment. Rotational power also depends on angular speed.
Can a torque conversion determine bolt load?
Not by itself. Bolt preload also depends on thread geometry, friction, lubrication and joint conditions.