Inch-Pounds to Foot-Pounds Converter
Convert torque between inch-pounds and foot-pounds, with newton-metres and kgf·m alongside, and check whether a spec suits your torque wrench.
1 ft-lb = 12 in-lb
Divide by 12
Torque is a force multiplied by the distance from the pivot. Both units use the pound-force, and they differ only in the distance: a foot is 12 inches, so 1 foot-pound is exactly 12 inch-pounds. The factor is exact, so there's no rounding in the conversion itself.
Inch-Pounds to Foot-Pounds Table
| in-lb | ft-lb | N·m |
|---|---|---|
| 12 in-lb | 1 | 1.36 |
| 24 in-lb | 2 | 2.71 |
| 36 in-lb | 3 | 4.07 |
| 48 in-lb | 4 | 5.42 |
| 60 in-lb | 5 | 6.78 |
| 84 in-lb | 7 | 9.49 |
| 96 in-lb | 8 | 10.85 |
| 100 in-lb | 8.33 | 11.3 |
| 120 in-lb | 10 | 13.56 |
| 144 in-lb | 12 | 16.27 |
| 180 in-lb | 15 | 20.34 |
| 240 in-lb | 20 | 27.12 |
| 300 in-lb | 25 | 33.9 |
| 360 in-lb | 30 | 40.67 |
Which Torque Wrench to Use
Specs in inch-pounds usually mean small fasteners, and they often fall below the bottom of a foot-pound wrench's scale. Click wrenches are least accurate near the ends of their range, so pick one where your target sits comfortably in the middle. Ranges vary by model, so check yours:
| Wrench | Typical range | Typical jobs |
|---|---|---|
| 1/4 in drive | about 20–200 in-lb | Small fasteners, trim, valve covers, bicycles |
| 3/8 in drive | about 10–80 ft-lb | General engine and chassis work |
| 1/2 in drive | about 25–250 ft-lb | Wheel lug nuts, suspension, large bolts |
Worked Example: a 100 in-lb Spec on a ft-lb Wrench
A valve cover bolt is specified at 100 in-lb. Your 3/8 in click wrench is marked in foot-pounds and starts at 10 ft-lb.
Step 1: Convert the spec
Step 2: Compare with the wrench range
The spec is 8.33 ft-lb, too low for this wrench. Use a 1/4 in inch-pound wrench instead, where 100 in-lb is mid-range. Rounding up to 10 ft-lb on the bigger wrench would overtighten the bolt by 20%.
The 12× Mix-Up
The most expensive torque mistake is reading the wrong unit. Setting 100 ft-lb when the spec says 100 in-lb applies twelve times the intended torque, which is enough to strip threads in aluminium or snap a small bolt. Going the other way leaves a fastener at a twelfth of its spec. If a number looks unusually high or low for the size of the bolt, check the unit before tightening.
Always use the torque value, sequence and any lubrication instructions from the manufacturer of the part. This page converts units. It doesn't tell you what a fastener should be tightened to.
in-lb, lb-in, ft-lb and lb-ft
You'll see the same units written several ways: in-lb, in·lbf, lb-in and lbf·in all mean inch-pounds of torque, and ft-lb, lb-ft and lbf·ft mean foot-pounds. Some engineering style guides prefer lb-ft for torque and keep ft-lb for energy (work), because torque and energy share the same dimensions. On a torque spec, though, they're the same unit and convert identically.
Frequently asked questions
How many inch-pounds are in a foot-pound?
Exactly 12, because a foot is 12 inches.
What is 50 in-lb in ft-lb?
4.17 ft-lb (50 ÷ 12). That's below most 3/8 in foot-pound wrenches, so use an inch-pound wrench.
Is a foot-pound bigger than an inch-pound?
Yes, 12 times bigger. That's why converting to foot-pounds gives a smaller number for the same torque.
Can I convert a ft-lb wrench reading to N·m too?
Yes. The converter shows newton-metres alongside: 1 ft-lb is 1.3558 N·m, so 10 ft-lb is 13.56 N·m.
Sources
- NIST Special Publication 811: pound-force, foot and inch definitions and torque conversion factors.
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