Torque Converter

Convert torque between newton-metres, pound-feet, inch-pounds, kgf·m and more, and work out horsepower or kW from torque and rpm (and back).

Torque

Unit

kN·m

0.1

N·cm

10000

lbf·ft

73.7562

lbf·in

885.075

ozf·in

14161.2

kgf·m

10.1972

kgf·cm

1019.72

dyn·cm

1.0000e+9

Torque ↔ horsepower at an rpm

Engine speed (rpm)

Horsepower

42.1295

PS (metric)

42.7138

Kilowatts

31.4159

Torque wrench chart

N·m to lb·ft and in·lb
N·m	lb·ft	in·lb	kgf·m
5	3.7	44	0.51
10	7.4	89	1.02
20	14.8	177	2.04
25	18.4	221	2.55
40	29.5	354	4.08
50	36.9	443	5.10
80	59.0	708	8.16
100	73.8	885	10.20
120	88.5	1062	12.24
150	110.6	1328	15.30
200	147.5	1770	20.39

How to use it

Type a torque value and pick its unit: every other unit updates as you type. Torque-wrench settings are commonly given in N·m in European manuals and in lb·ft or in·lb in American ones, so the chart below covers the everyday wrench range.

For engines, enter the torque and the engine speed in rpm to get power in horsepower, metric PS and kilowatts — or enter the power and rpm to get the torque.

The conversion factors

1 lbf·ft = 1.355 818 N·m and 1 lbf·in = 0.112 985 N·m, from the exact definitions 1 lbf = 4.448 221 615 260 5 N and 1 ft = 0.3048 m (NIST Special Publication 811). 1 kgf·m = 9.806 65 N·m exactly. There are 12 in·lb in each ft·lb.

Power is torque times rotational speed: P (W) = torque (N·m) × 2π × rpm ÷ 60. In US units that becomes hp = lb·ft × rpm ÷ 5252, because one mechanical horsepower is 33 000 ft·lbf per minute and 33 000 ÷ 2π = 5252.1. That is also why every engine's torque and horsepower curves cross at 5252 rpm when plotted in lb·ft and hp.

Frequently asked questions

How many N·m is 1 lb-ft?

1.3558 N·m. To go the other way, 1 N·m is 0.7376 lb·ft.

How do I convert in-lb to ft-lb?

Divide by 12: 120 in·lb is 10 ft·lb.

Is lb-ft the same as ft-lb?

For torque, yes — both mean a pound-force acting at one foot. Engineers often write lb·ft for torque and ft·lb for energy (work) to keep the two apart.

How do I get horsepower from torque?

Horsepower = torque in lb·ft × rpm ÷ 5252. 300 lb·ft at 4000 rpm is about 228 hp.