The factor, and a shortcut
One newton-metre is 8.85 inch-pounds. For a quick check, multiply the Nm figure by about 9 and shade down slightly: 5 Nm is roughly 45 (44.3 exactly), 10 Nm is roughly 90 (88.5). The estimate runs about 1.5% high.
Common torque values
| Newton-metres | Inch-pounds | Foot-pounds |
|---|---|---|
| 0.5 Nm | 4.43 in-lb | 0.37 ft-lb |
| 1 Nm | 8.85 in-lb | 0.74 ft-lb |
| 2 Nm | 17.70 in-lb | 1.48 ft-lb |
| 5 Nm | 44.25 in-lb | 3.69 ft-lb |
| 10 Nm | 88.51 in-lb | 7.38 ft-lb |
| 25 Nm | 221.27 in-lb | 18.44 ft-lb |
| 50 Nm | 442.54 in-lb | 36.88 ft-lb |
Small electronics and precision work sit at the low end (a phone case screw is around 0.5 to 1.5 in-lb); the foot-pounds column is there to catch the common in-lb/ft-lb mix-up.
The mistake that damages hardware
- Inch-pounds are not foot-pounds. 12 in-lb = 1 ft-lb. A torque wrench set to "8" reads inch-pounds on one tool and foot-pounds on another; the second is 12 times tighter.
- Torque is not weight. "in-lb" is a turning force (a pound of force at one inch of leverage), not "lb" of mass. They are unrelated quantities.
- Small values still matter. On watches, phones and circuit boards a 0.5 in-lb difference is real. Under-torque lets parts work loose; over-torque strips threads or cracks housings.
Common questions
How many inch-pounds are in one newton-metre?
One newton-metre is 8.85 inch-pounds (exactly 8.8507). To go the other way, one inch-pound is about 0.113 Nm.
What is the difference between inch-pounds and foot-pounds?
Twelve inch-pounds make one foot-pound, because there are 12 inches in a foot. Inch-pounds are used for small, precise fasteners; foot-pounds for larger ones. Mixing them up is a 12-fold error.
Is a newton-metre the same as a joule?
They share the same units, but not the same meaning. A newton-metre of torque is a turning force; a joule is energy from a force acting over a distance. By convention, torque is written in Nm and energy in joules.
