Torque Converter

Torque is the twisting force an engine or a spanner produces, and every workshop manual quotes it differently: newton-metres in Europe, pound-feet in the United States, pound-inches for smaller fasteners and kilogram-force metres elsewhere. A 250 N·m wheel nut is 184.39 lb·ft, and quoting the wrong system by a factor of 12 — foot versus inch — is how bolts get stripped. Convert once here and every manual agrees.

Enter values

Results

In pound-feet (lb·ft): 73.7562
In kilonewton-metres (kN·m): 0.1
In kilogram-force metres (kgf·m): 10.1972
In pound-inches (lb·in): 885.0746
Exact factor: 1 N·m = 0.7375621493 lb·ft

How is the Torque Converter calculated?

Enter the torque, choose the unit on the spec sheet, and choose the unit your tool is calibrated in. The headline result carries the answer, while the rows beneath repeat the same torque in newton-metres, kilonewton-metres, pound-feet and pound-inches so the familiar figure stays visible. The final row prints the exact factor — 1 N·m = 0.7375621493 lb·ft — so you can check the workshop conversion on paper. Decimals are welcome and values run to a billion.

Formula

Everything passes through newton-metres: newton-metres = value × from-unit factor, then target = newton-metres ÷ to-unit factor. Exact factors: 1 kN·m = 1,000 N·m · 1 kgf·m = 9.80665 N·m · 1 lb·ft = 1.3558179483314004 N·m · 1 lb·in = 1.3558179483314004 ÷ 12 N·m, and 1 lb·ft = 12 lb·in exactly.

Example

A wheel nut specified at 250 N·m is 250 × 0.7375621493 = 184.39 lb·ft or 2,212.69 lb·in; a torque wrench reading in foot-pounds needs 184.39, not 250. A 300 lb·ft truck figure is 300 × 1.3558179483314004 = 406.75 N·m, and 110 lb·ft of a motorcycle engine converts to 149.14 N·m. Metric mechanics may prefer kgf·m: 250 N·m ÷ 9.80665 = 25.49 kgf·m.

Things to remember

Torque and power are different quantities, but both live or die by unit discipline: one pound-foot is exactly twelve pound-inches, and one newton-metre is 0.7375621493 lb·ft. Quote the unit with the number, and a wrench bought in the wrong system stops being a hazard.

Frequently Asked Questions

How many pound-feet are in one newton-metre?

0.7375621493 lb·ft. Multiply newton-metres by that figure, so 100 N·m is 73.76 lb·ft and 250 N·m is 184.39 lb·ft. Reverse it by dividing pound-feet by the same number, or multiplying by 1.3558179483314004.

Why is my wrench in foot-pounds but the manual in N·m?

Different regions settled on different systems, and neither is going away. Convert the manual's figure instead of guessing: multiply newton-metres by 0.7375621493 to get foot-pounds, so a 110 N·m specification is 81.13 lb·ft on the wrench scale.

What is the difference between lb·ft and lb·in?

A factor of twelve: a pound-inch is a pound-force applied one inch from the pivot and a pound-foot the same force one foot away. One lb·ft = 12 lb·in, so 100 lb·ft equals 1,200 lb·in — the confusion that turns a snug fastener into a stripped thread.

How is torque related to horsepower?

Power equals torque times rotational speed: horsepower = torque in lb·ft × rpm ÷ 5,252, which is why the two curves on a dyno chart cross at 5,252 rpm. An engine making 250 lb·ft at that speed is producing 250 hp at that point.