Torque Calculator
Find torque from a force on a lever arm, or from a motor’s power and speed, in lb-ft, lb-in and N·m.
–
Lb-Ft.
- Pound-inches
- Newton-meters
- Kilogram-meters
- Effective force
- Also Known As
Saved Torques
Items you add are saved in this browser.
| Name | From | Lb-Ft. | N·m | Remove |
|---|
How to Calculate Torque
Torque is a twisting force: the force times the distance from the pivot at which it acts. Push 50 pounds at the end of an 18-inch wrench and you apply 50 × 1.5 = 75 lb-ft. If you push at an angle, only the part of the force across the arm counts.
Torque = force × lever arm × sin(angle)
From power: lb-ft = hp × 5,252 ÷ RPM N·m = kW × 9,549 ÷ RPM
5,252 comes from 33,000 ft·lb per minute in a horsepower divided by 2π. 9,549 is 60,000 ÷ 2π.
Worked Example
Torque Unit Conversions
| 1 Unit of | lb-ft | lb-in | N·m |
|---|---|---|---|
| lb-ft | 1 | 12 | 1.3558 |
| lb-in | 0.08333 | 1 | 0.11298 |
| N·m | 0.73756 | 8.8507 | 1 |
| kgf·m | 7.2330 | 86.796 | 9.8067 |
Tips
A cheater bar multiplies torque by lengthening the arm, which is why it can snap bolts. For bolt tightening, use the bolt torque calculator, which works from the bolt size and grade.