Torque Converter
Convert torque between newton-metres, newton-centimetres, kilonewton-metres, pound-force feet, pound-force inches, and kilogram-force metres.
How to use this tool
- Enter torque and from unit in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your pound-force feet and the full breakdown beneath it.
Formula
All torque values are normalised to newton-metres (N·m), then converted to each output unit:
N·m = value × factorfrom
Factors: 1 N·cm = 0.01 N·m, 1 kN·m = 1,000 N·m, 1 lbf·ft = 1.355818 N·m, 1 lbf·in = 0.112985 N·m, 1 kgf·m = 9.80665 N·m.
How it works
The converter pivots on newton-metres, the SI unit of torque. The input is multiplied by its N·m equivalent to obtain a base value, then each output is obtained by dividing that base by the target unit's factor. The kgf·m factor of 9.80665 is the standard acceleration due to gravity, which is what relates a kilogram-force to newtons.
Common mistake: Confusing pound-force feet (lbf·ft) with pound-feet (lb·ft). In colloquial use 'ft-lbs' is almost always intended as lbf·ft (force × distance), but in some older texts 'lb·ft' refers to a moment of inertia (mass × distance²), which has entirely different units and cannot be converted to N·m using these factors.
Worked example
Convert 1 N·m to all torque units
- Input: 1 N·m. N·m is the pivot unit, so base = 1.
- N·cm = 1 / 0.01 = 100; kN·m = 1 / 1,000 = 0.001.
- lbf·ft = 1 / 1.355818 ≈ 0.73756; lbf·in = 1 / 0.112985 ≈ 8.8507.
- kgf·m = 1 / 9.80665 ≈ 0.10197.
1 N·m = 100 N·cm = 0.001 kN·m = 0.73756 lbf·ft = 8.8507 lbf·in = 0.10197 kgf·m.
Common mistakes to avoid
- Confusing torque (N*m) with energy (also N*m or joules) -- both have the same units, but torque is a rotational force vector while energy is a scalar; they are not interchangeable.
- Mixing up pound-force feet (lbf*ft) and pound-force inches (lbf*in) when reading torque specs -- a bolt torqued to 30 lbf*ft is 360 lbf*in; using the wrong unit can damage fasteners.
- Forgetting that kilogram-force metres (kgf*m) uses gravitational force (9.80665 N per kgf) -- 1 kgf*m = 9.80665 N*m, not 1 N*m.
Key terms
- Newton-metre (N·m)
- The SI unit of torque, equal to the torque produced by a force of one newton acting perpendicularly at a distance of one metre from the pivot. Also equal to one joule of energy, though the two are dimensionally distinct quantities.
- Pound-force foot (lbf·ft)
- A US customary torque unit equal to the torque from one pound-force applied one foot from the pivot. Engine output torque is commonly rated in lbf·ft in North America.
- Kilogram-force metre (kgf·m)
- A metric gravitational unit of torque equal to 9.80665 N·m. Still used in some engineering contexts in countries that historically used the MKgS system.
- Torque
- A rotational equivalent of linear force — the tendency of a force to rotate an object about an axis. Torque equals force multiplied by the perpendicular distance from the axis (the moment arm).
Frequently asked questions
- What is the difference between torque and energy if both are measured in newton-metres?
- Torque (N*m) is the rotational equivalent of force applied at a distance -- it describes how hard something twists. Energy (J = N*m) is work done or heat transferred. Despite identical units, they are physically distinct quantities and cannot be added or compared.
- How do I convert ft-lb to N*m for a torque wrench?
- Multiply ft-lb by 1.35582. So 100 ft-lb is approximately 135.6 N*m. Many torque wrenches display both scales.
- Why do engine specs sometimes list torque in kgf*m?
- Older Japanese and European engineering documents used kilogram-force metres before SI standardisation. 1 kgf*m = 9.80665 N*m. A 30 kgf*m engine torque figure equals roughly 294 N*m or 217 lb-ft.