Newton-meters to Inch-pounds Converter

Low torques are where inch-pounds earn their place. Bicycle stems, seatpost clamps and handlebar bolts often have a small Nm figure printed beside them, and quarter-inch-drive torque wrenches and screwdrivers are frequently scaled in in-lb. The same goes for valve covers, sensor mounts, electronics enclosures and scope or accessory rails.

One newton-metre is 8.8507 in-lb. Rounding that to 9 is easy but 1.7% high: 5 Nm × 9 = 45 in-lb against 44.2537. Using 8.85 is within 0.01% and gives 44.25. A practical routine is to multiply by 9 and subtract about 1.5% of the result, which for 5 Nm means 45 − 0.7 = 44.3.

The worst error at small torques is reading in-lb and ft-lb as if they were the same. One foot-pound is twelve inch-pounds, so a 5 Nm stem bolt is either 44.25 in-lb or 3.6878 ft-lb. Set a foot-pound wrench to 44 by mistake and you apply twelve times the intended torque, which can crack a carbon part or strip a soft thread.

Before tightening, read the unit printed on the wrench scale itself, not just the number, and check it against the To unit selected on this page. If a part lists its spec in both Nm and in-lb, use the one that matches your wrench and skip the conversion entirely.

Rounding to the nearest whole in-lb moves the setting by up to 0.5 in-lb, which is 0.0565 Nm. At 5 Nm that is about 1.1%, and at 2 Nm it is about 2.8%. Fractional specs convert just as easily: 0.5 Nm is 4.4254 in-lb, 1.5 Nm is 13.2761 in-lb and 2.5 Nm is 22.1269 in-lb.

Hobby servos and small motors are often rated in kilogram-centimetres. The menu has kilogram-metres (kgf·m) instead, so divide a kgf·cm figure by 100 first. A 20 kgf·cm rating is 0.2 kgf·m, which converts to 17.3592 in-lb or 1.9613 Nm.