How this calculator works
One foot-pound is the torque from one pound-force applied at a one-foot lever arm. With the international pound-force of 4.4482216152605 N and a foot of exactly 0.3048 m, one foot-pound is exactly 1.3558179483314004 N-m. Dividing a newton-metre value by that factor gives foot-pounds.
Formula
ft-lb = N-m / 1.3558179483314004. N-m = ft-lb x 1.3558179483314004. One ft-lb is also 12 lbf-in, and one N-m is 100 N-cm.
Worked example
100 N-m = 100 / 1.3558179483314004 = 73.7562 lbf-ft. 100 lbf-ft = 135.582 N-m. A value of 50 N-m is 36.8781 lbf-ft, or 442.537 lbf-in.
Advertisement
Frequently asked questions
What is the quick mental conversion?
One newton-metre is about 0.74 foot-pounds. To go the other way, multiply foot-pounds by about 1.36. Use the exact values here when the torque specification matters.
Why do car specifications use both units?
Manufacturers publish in the unit used by their main market. A Canadian or European specification usually uses N-m, while a US specification often uses lb-ft, so owners compare them.
Is lb-ft the same as ft-lb?
Yes, when both mean torque. The order of the words does not change the product, but some industries write lbf-ft to distinguish torque from the energy foot-pound.