How this conversion works
Torque is a force multiplied by the distance from the pivot. Each unit is a force unit times a length unit, so it converts by multiplying both factors.
One pound-force foot is 4.4482216152605 N × 0.3048 m ≈ 1.355818 N·m. One pound-force inch is one twelfth of that, about 0.112985 N·m.
Formula: result = value × (base units per source unit) ÷ (base units per target unit)
Where this conversion is used
- Wheel lug nut and engine fastener specifications in N·m or ft-lb.
- Setting a torque wrench scaled in different units.
- Small electronics and bicycle components specified in in-lb or N·m.
- Electric motor and engine torque figures.
Worked example: Wheel nut spec of 100 lbf·ft in N·m
- One lbf·ft ≈ 1.355818 N·m.
- 100 × 1.355818 = 135.58 N·m.
Unit definitions
| Unit | In newton-meters | Note |
|---|---|---|
| Newton-meter (N·m) | 1 | |
| Kilonewton-meter (kN·m) | 1,000 | |
| Newton-centimeter (N·cm) | 0.01 | |
| Newton-millimeter (N·mm) | 0.001 | |
| Pound-force foot (lbf·ft) | 1.3558179483 | |
| Pound-force inch (lbf·in) | 0.112984829 | |
| Ounce-force inch (ozf·in) | 0.0070615518 | |
| Kilogram-force meter (kgf·m) | 9.80665 | |
| Kilogram-force centimeter (kgf·cm) | 0.0980665 | |
| Dyne-centimeter (dyn·cm) | 1e-7 |
Newton-meters to pound-force feet
| Newton-meter (N·m) | Pound-force foot (lbf·ft) |
|---|---|
| 1 | 0.7376 |
| 5 | 3.6878 |
| 10 | 7.3756 |
| 25 | 18.4391 |
| 50 | 36.8781 |
| 100 | 73.7562 |
| 150 | 110.6343 |
| 200 | 147.5124 |
Pound-force feet to newton-meters
| Pound-force foot (lbf·ft) | Newton-meter (N·m) |
|---|---|
| 10 | 13.5582 |
| 20 | 27.1164 |
| 50 | 67.7909 |
| 80 | 108.4654 |
| 100 | 135.5818 |
| 120 | 162.6982 |
| 150 | 203.3727 |
Newton-meters to pound-force inches
| Newton-meter (N·m) | Pound-force inch (lbf·in) |
|---|---|
| 1 | 8.8507 |
| 2 | 17.7015 |
| 5 | 44.2537 |
| 10 | 88.5075 |
| 25 | 221.2686 |
Things to watch for
- Torque (N·m) and energy (J) share the same SI base units but are different quantities. Use the Energy Converter for foot-pounds of work.
Precision and sources
Results are calculated from the definitions above and rounded to 12 significant digits; the converter shows up to eight decimal places and the tables four. Reference: NIST Special Publication 811, Guide for the Use of the International System of Units, Appendix B.
Frequently asked questions
Are ft-lb and lb-ft the same?
For torque, mechanics use both names for the pound-force foot. This converter treats them as the same unit (≈ 1.3558 N·m).
How do I convert in-lb to ft-lb?
Divide by 12. For example, 120 lbf·in is 10 lbf·ft.
Should I round a torque spec?
Follow the manufacturer's value and tolerance. Converted figures are mathematically exact but your wrench's accuracy and scale steps limit what you can set.