Torque Converter

N·m, ft·lb, in·lb and kgf·m side by side — for torque wrenches, wheel nuts and carbon bike parts.

Conversion table

Torque	In foot-pounds
1	0.73756 ft·lbf
2	1.4751 ft·lbf
3	2.2127 ft·lbf
4	2.9502 ft·lbf
5	3.6878 ft·lbf
10	7.3756 ft·lbf
15	11.0634 ft·lbf
20	14.7512 ft·lbf
25	18.439 ft·lbf
30	22.1268 ft·lbf
40	29.5024 ft·lbf
50	36.8781 ft·lbf
60	44.2537 ft·lbf
70	51.6293 ft·lbf
75	55.3171 ft·lbf

🔧 Torque landmarks

1 ft·lb1.3558 N·m
1 N·m0.7376 ft·lb
1 ft·lb12 in·lb
1 kgf·m9.807 N·m

Using a torque wrench properly

Check whether the manual means foot-pounds or inch-pounds before setting the wrench. Getting that wrong is a factor of twelve, and on a small bolt it means shearing it off.
Wind a click wrench back to its lowest setting before storing it. Leaving the spring compressed is the fastest way to lose calibration.
Never use a torque wrench to loosen a fastener. It is a measuring instrument, and breaking a seized bolt with it damages the mechanism.
Carbon bicycle parts are the strictest case: 5 N·m means 5, and half a turn more can crack a seat post or a bar.

What torque is, and why it is not energy

Torque is a twisting effort: a force applied at a distance from a pivot. Ten newtons pushing on a spanner 0.3 metres long gives 3 newton-metres, and the same 3 N·m can come from thirty newtons on a spanner a tenth as long. That is why a longer bar makes a bolt easier to turn. The newton-metre happens to have the same dimensions as the joule, but the two are never interchangeable: a joule measures work done along a line, while torque is a moment about an axis, and by convention torque is always written in N·m and never in joules.

Torque and power are not the same thing

A spec sheet quotes both because they answer different questions. Torque is the twisting force available at a given moment; power is how quickly that twist can do work, so it depends on both torque and revolutions. The link is simple: power in kilowatts equals torque in newton-metres times rpm divided by 9,549. A diesel making 400 N·m at 2,000 rpm produces 84 kW, while a small petrol engine making 200 N·m at 6,000 rpm produces 126 kW from half the torque. Torque is what you feel pulling away; power is what decides top speed.

Typical tightening figures

Passenger car wheel nuts: 100–140 N·m, which is 74–103 ft·lb. Always check the specific vehicle.
Spark plugs: 20–30 N·m (15–22 ft·lb), and less on aluminium heads.
Engine oil drain plug: 25–40 N·m. Overtightening strips the sump thread, which is an expensive repair.
Bicycle stem and seat-post bolts on carbon: 4–6 N·m, roughly 35–53 in·lb.
Small electronics and optics: 0.5–2 N·m, better read in kgf·cm or ozf·in.
Truck wheel nuts: 450–700 N·m, far beyond hand tools and normally set with a calibrated wrench.

Where torque readings go wrong

Foot-pounds mistaken for inch-pounds. The factor is twelve, and it goes both ways: too loose or sheared clean off.
Threads that are dry when the manual assumes lubricated, or the reverse. Lubrication can change the clamping force by 30% at the same torque.
An extension bar changes the effective torque at the fastener unless it is in line with the wrench axis.
Click wrenches are typically accurate to about ±4%, and only within the middle of their range — not at the very bottom of the scale.
Old manuals in kgf·m read deceptively small: 11 kgf·m is 108 N·m, not 11.
Torque-to-yield bolts, common on modern cylinder heads, are tightened by angle after a preload and cannot be reused.

Worked examples

The conversions people actually need at the wheel

The manual says 110 N·m

110 ÷ 1.35582 = 81.1 ft·lb
Set an imperial wrench to 81 ft·lb
In inch-pounds that would be 973 — clearly the wrong scale for this job

110 N·m = 81.1 ft·lb

An old manual says 2.5 kgf·m

2.5 × 9.80665 = 24.5 N·m
24.5 ÷ 1.35582 = 18.1 ft·lb
A typical spark-plug figure, which is a good sanity check

2.5 kgf·m = 24.5 N·m = 18.1 ft·lb

Frequently Asked Questions

How many newton-metres is 1 foot-pound?

1.35582 N·m. Going the other way, 1 N·m is 0.73756 ft·lb. A rough check in your head: multiply foot-pounds by four and divide by three, so 80 ft·lb is about 107 N·m.

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

A factor of twelve, because there are twelve inches in a foot. So 10 ft·lb is 120 in·lb. American manuals use inch-pounds for small fasteners precisely so the numbers stay readable, and mistaking one for the other is the classic way to shear a small bolt.

What is kgf·m and why does my old manual use it?

Kilogram-force metre, the torque produced by one kilogram-force acting a metre from the axis: 9.80665 N·m. It was standard in Japanese and older European manuals before SI units took over. The danger is that the numbers look small — 11 kgf·m is 108 N·m — so reading it as newton-metres leaves a wheel nut dangerously loose.

Is a newton-metre the same as a joule?

Dimensionally yes, in practice never. A joule is work: a force moving something along its own direction. Torque is a moment about an axis, and the distance in it is perpendicular to the force rather than along it. Both come out as N·m in algebra, but writing a torque in joules is wrong by convention and confusing in any technical document.

How much torque should a car wheel nut have?

Most passenger cars fall between 100 and 140 N·m, which is 74 to 103 ft·lb, but the correct figure is in the vehicle handbook and varies with stud size and wheel material. Tightening in a star pattern matters as much as the number, and alloy wheels should be rechecked after fifty to a hundred kilometres.

Does torque tell me how powerful an engine is?

Only half the story. Power equals torque times rotational speed: in kilowatts it is torque in N·m times rpm divided by 9,549. An engine with modest torque spinning fast can out-power one with high torque turning slowly, which is why spec sheets always print both figures and the rpm at which each occurs.