Pound-Feet to Newton-Meters

Pound-feet and newton-meters

A pound-foot is one pound-force on a one-foot lever: about 1.3558 N·m. US car engine torque and lug-nut and bolt specs use lb·ft, commonly called foot-pounds.

A newton-meter is the torque of one newton acting on a one-meter lever arm. Bolt torque specs, car engine torque in metric countries and torque wrenches use N·m.

Worked example

Convert 80 lbf·ft: 80 × 1.355817948 = 108.4654359, so 80 pound-feet is 108.4654359 newton-meters. Likewise 20 lbf·ft = 27.11635897 N·m.

Estimating in your head

Multiply by 1.4 for a quick figure; it is off by about 3.3%. For 80 lbf·ft that gives 112 N·m, against 108.465 exactly.

Going the other way

To convert newton-meters to pound-feet, divide by 1.355817948 (or multiply by 0.737562149277). The swap button between the boxes opens that page.

N·m = lbf·ft × 1.355817948

1 lbf·ft = ≈ 1.355817948 N·m and 1 N·m = 1 N·m, both by definition, so the factor is their ratio: 1.355817948 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.