Inch-Pounds to Newton-Metres Calculator — in·lbf to N·m
Torque specs on small fasteners and tools are often given in inch-pounds (in·lbf) in the US, while metric standards use newton-metres (N·m). Enter your torque in inch-pounds to convert to N·m, ft·lbf and other common torque units.
in·lbf
1 in·lbf = 0.112985 N·m (from 1 lbf = 4.44822 N, 1 in = 0.0254 m)
- 1
Conversion factor
4.44822 N/lbf × 0.0254 m/in = 0.112985One in·lbf equals one pound-force (4.44822 N) at one inch (0.0254 m) — exact SI definitions. - 2
Newton-metres
100 × 0.112985 = 11.2985
How does this calculator work?
Multiply inch-pounds by 0.112985 to get newton-metres: N·m = in·lbf × 0.112985. This comes from 1 lbf = 4.44822 N and 1 in = 0.0254 m. For foot-pounds divide inch-pounds by 12 first.
Formula
How this is calculated
Torque is a force applied at a distance from a pivot point. The SI unit is the newton-metre (N·m = 1 N applied at 1 m). The inch-pound (in·lbf) is the US customary equivalent: 1 lbf applied at 1 inch from the pivot.
The conversion uses two exact SI-defined factors: 1 pound-force = 4.44822161526 N (derived from the international pound of 0.45359237 kg and standard gravity 9.80665 m/s²) and 1 inch = 0.0254 m (defined exactly in 1959). Multiplying those gives 1 in·lbf = 4.44822161526 × 0.0254 ≈ 0.112984829 N·m.
For context: there are exactly 12 inch-pounds in one foot-pound. The kilogram-force centimetre (kgf·cm) is a legacy metric unit still common in older engineering specs — 1 N·m ≈ 10.197 kgf·cm. This calculator assumes inch-pound-force (in·lbf), not inch-pound-mass (in·lbm), which is a unit of moment of inertia and unrelated to torque.
Frequently asked questions
Exactly 4.4482216152605 N/lbf × 0.0254 m/in ≈ 0.112984829 N·m. For practical purposes, multiply inch-pounds by 0.11299 to get newton-metres.
In·lbf (inch-pound-force) is a unit of torque: a force of one pound-force acting at one inch. In·lbm (inch-pound-mass) is a unit of moment of inertia. This calculator converts torque — always use in·lbf when torque specs are given.
Inch-pounds are used for smaller torque values, such as small engine bolts, electronic connectors and precision fasteners. Foot-pounds (1 ft·lbf = 12 in·lbf) are used for larger torques like wheel nuts and engine head bolts.
Also known as
TG we-Calculate Editorial Team. (2026). Inch-Pounds to Newton-Metres Calculator — in·lbf to N·m [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/inch-lbs-to-nm-calculator
TG we-Calculate Editorial Team. "Inch-Pounds to Newton-Metres Calculator — in·lbf to N·m." TG we-Calculate. 2026. https://we-calculate.com/calculator/inch-lbs-to-nm-calculator.
TG we-Calculate Editorial Team, "Inch-Pounds to Newton-Metres Calculator — in·lbf to N·m," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/inch-lbs-to-nm-calculator
@misc{wecalculate_inch_lbs_to_nm_calculator, title = {Inch-Pounds to Newton-Metres Calculator — in·lbf to N·m}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/inch-lbs-to-nm-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?