Torque Converter: N·m, ft·lb, kgf·m & More
Convert between newton-metres, foot-pounds, inch-pounds, kilogram-force metres, and other torque units used in engineering, automotive, and tool specifications.
How this torque converter maps eight rotational force units back to the newton-metre
Torque is a rotational force, a twisting effort, and its units always combine a force term with a distance term. That structure is visible in almost every unit name here, foot-pound, kilogram-force metre, ounce-inch. Reading the name tells you the force unit and the lever arm length it was measured over. This tool normalizes every one of those combinations against the newton-metre, the SI derived unit, so any pair converts through one shared reference point.
The calculation runs entirely in your browser using plain JavaScript. No value you enter is transmitted anywhere.
How a torque conversion runs
| Unit | Symbol | N·m per unit |
|---|---|---|
| Newton-metre | N·m | 1 |
| Kilonewton-metre | kN·m | 1,000 |
| Foot-pound | ft·lb | 1.3558179483 |
| Inch-pound | in·lb | 0.1129848290 |
| Ounce-inch | oz·in | 0.0070615518 |
| Kilogram-force metre | kgf·m | 9.80665 |
| Kilogram-force centimetre | kgf·cm | 0.0980665 |
| Gram-force centimetre | gf·cm | 0.0000980665 |
Foot-pound versus newton-metre, a units culture divide
Foot-pound
Standard in US automotive and construction torque wrenches, built from the imperial foot and the pound-force. It reflects the customary unit system still dominant in American manual trades and tool manufacturing.
Newton-metre
The SI coherent derived unit, built from the newton and the metre, used on essentially all vehicle and equipment specifications outside the United States and increasingly on international manufacturer documentation everywhere.
Torque references
- BIPM SI Brochure defines the newton-metre as the coherent SI unit for the moment of force, built from the newton and the metre.
- NIST SI derived units reference lists torque and moment of force alongside their base unit composition.
- ISO 80000-4 is the international standard covering mechanics quantities including moment of force and its accepted units.
Torque in mechanics and spec sheets
Converting a car manufacturer’s newton-metre torque spec into foot-pounds for a US made torque wrench, checking a bicycle stem bolt’s newton-metre rating against an older imperial tool, reading an engineering spec sheet given in kilogram-force metres against a modern SI datasheet, and translating small fastener torque values in ounce-inches for electronics assembly work.
FAQ: Torque Converter
Multiply the newton-metre value by 0.7376 to get foot-pounds (or divide by 1.3558179483, the more precise factor this tool uses). For example, 10 N·m equals approximately 7.38 ft·lb. This conversion comes up constantly when comparing a metric torque spec against a torque wrench calibrated in imperial units.
Both measure the same kind of rotational force, but inch-pounds are used for smaller torque values (common on electronics, small fasteners, and precision assembly) while foot-pounds are used for larger values (common on automotive lug nuts and structural bolts). There are exactly 12 inch-pounds in 1 foot-pound, since a foot is 12 inches.
Kilogram-force metres (kgf·m) express torque using kilogram-force, a now-legacy unit of force based on Earth’s standard gravity, rather than the newton, the SI-derived unit of force. One kgf·m equals 9.80665 N·m, and you’ll mainly encounter kgf·m in older technical manuals, especially from regions that historically used kilogram-force in engineering specs.
Small rounding differences accumulate if a spec sheet already rounded its converted value, for example, if a manual says ’74 ft·lb (100 Nm)’, that’s a rounded approximation, not an exact match (100 N·m is actually 73.76 ft·lb). Always convert from the original, most precise source value when accuracy matters, rather than re-converting an already-rounded number.
Yes, over-torquing can stretch or shear a bolt, strip threads, or crack the material being fastened, while under-torquing can allow a joint to loosen under vibration or load, which is a common cause of mechanical failure. Always follow the manufacturer’s specified torque value and unit exactly, and use a calibrated torque wrench rather than estimating by feel.
Yes, the same conversion factors apply regardless of application, whether you’re torquing a car’s lug nuts (typically 80-100 ft·lb) or a small electronics screw (often specified in inch-pounds or even ounce-inches). Just make sure you’re reading the correct unit off the original spec before converting.
From the blog
Reading around units
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