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ToolBoxGenie

Torque Converter

Converters · Added 15 August 2026

Convert torque between newton metres, pound-force feet, kilogram-force metres and the inch-based units used for small fasteners. Torque settings are one of the few places where getting a conversion wrong has immediate physical consequences — a bolt tightened to 100 lb-ft when the spec said 100 N·m is over a third too tight.

Result

1 lbf·ft in newton metre

1.35581795 N·m

1 lbf·ft = 1.35581795 N·m

The same value in every unit

Newton metre (N·m)
1.35581795
Newton centimetre (N·cm)
135.581795
Millinewton metre (mN·m)
1,355.81795
Kilonewton metre (kN·m)
0.00135581795
Kilogram-force metre (kgf·m)
0.138254954
Kilogram-force centimetre (kgf·cm)
13.8254954
Pound-force foot (lbf·ft)
1
Pound-force inch (lbf·in)
12
Ounce-force inch (ozf·in)
192
Dyne centimetre (dyn·cm)
13,558,179.5

A newton metre and a joule have the same dimensions but describe different things: torque is a twist about an axis, energy is work done. Torque is always written N·m for that reason, never J.

How to use the torque converter

  1. 1Enter the torque value from your specification.
  2. 2Select the unit it is given in — check carefully whether it is foot-pounds or inch-pounds.
  3. 3Choose the unit your torque wrench is calibrated in.
  4. 4The reference table shows the value in every unit at once.
  5. 5Swap the units to convert back.

Examples

Car wheel nuts

Input
120 N·m
Result
88.51 lbf·ft · 12.24 kgf·m

A typical wheel nut specification. Always use the figure from your vehicle's manual.

Small fastener

Input
25 lbf·in
Result
2.825 N·m · 300 lbf·in equivalent check

Inch-pounds are used for small screws. One foot-pound is twelve inch-pounds — a factor easy to miss.

Engine output torque

Input
300 lbf·ft
Result
406.75 N·m · 41.48 kgf·m

Engine torque figures are quoted in lb-ft in the US and N·m almost everywhere else.

About the torque converter

What torque actually measures

Torque is the twisting effect of a force applied at a distance from an axis of rotation. Push on a spanner with 100 newtons at half a metre from the bolt and you apply 50 newton metres. The same push at a quarter of a metre gives 25 — half the leverage, half the torque. This is why a longer spanner makes a bolt easier to turn, and why torque specifications assume the wrench is being used correctly rather than with an extension bar.

Only the component of force perpendicular to the lever arm counts. Pulling along the length of a spanner produces no torque at all, however hard you pull. In practice this means a torque wrench should be pulled at right angles to its handle, which is one of the reasons a click-type wrench is set up to be used with a particular grip position.

The distinction between torque and power matters for engines. Torque is the twisting force available; power is torque multiplied by rotational speed. An engine can produce large torque at low revs and modest power, or moderate torque at high revs and considerable power. Neither figure alone describes what a vehicle feels like to drive.

Getting a torque setting right in practice

The most common practical failures are unit confusion and tool misuse, in that order. Confusing inch-pounds with foot-pounds is a twelvefold error, and confusing newton metres with pound-force feet is about 1.36 either way — enough to strip an aluminium thread or leave a joint loose. Reading the unit on the specification and on the wrench, both times, prevents nearly all of it.

Thread condition is the next variable, and it is invisible. A torque figure assumes a particular friction between the threads, so the same reading produces meaningfully different clamping force on a dry, an oiled and a thread-locked bolt. Manufacturer specifications say which condition they assume; where they do not, dry is the usual default.

Finally, torque wrenches need care to stay accurate. A click-type wrench should be wound back to its lowest setting for storage so the internal spring is not left compressed, and any wrench that has been dropped should be treated as suspect until recalibrated. A wrench that reads 10% low is worse than no wrench at all, because it produces confident, consistently wrong results.

Frequently asked questions

What is the difference between foot-pounds and inch-pounds?
A factor of twelve, and confusing them is the most common torque error there is. One pound-force foot is twelve pound-force inches. Inch-pounds are used for small fasteners where foot-pounds would give awkward fractions — electronics, instrument panels, small engine components. If a specification seems implausibly high or low by roughly twelve times, this is almost certainly why.
Are newton metres and joules the same thing?
They have identical dimensions but describe different quantities. A joule is work done — a force moving something through a distance. A newton metre of torque is a twisting effect about an axis, where the distance is a lever arm perpendicular to the force rather than a distance travelled. By convention torque is always written N·m and never J, precisely to keep the two apart in engineering documents.
Does it matter whether I write lb-ft or ft-lb?
Both are widely used for torque and mean the same thing in practice. Strictly, torque is force times lever arm, so pound-force foot (lbf·ft) is the more logical order, and some standards reserve foot-pound (ft·lbf) for energy. In the automotive world the two are used interchangeably and context makes it clear. What genuinely matters is the foot-versus-inch distinction, not the word order.
Why do torque specifications matter so precisely?
Because tightening a bolt is really about stretching it. A correctly torqued bolt is a stretched spring holding the joint together, and the torque figure is an indirect way of reaching the right tension. Too little and the joint can loosen under vibration; too much and the bolt yields, losing its clamping ability, or the thread strips. Since the relationship between torque and tension also depends on thread friction, specifications usually state whether threads should be dry or lubricated — applying a dry-thread figure to an oiled bolt over-tightens it substantially.

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