# How to Calculate Rotational Torque

by Ryan MenezesRotational torque measures a force's tendency to rotate an object. To calculate it, you need to know how large the force is and the length between the axis and the point of force application.

### Step 1

Convert force to Newtons (N). To convert pounds to Newtons, multiply by 4.45. For example, if force equals 100 lbs.:

100 * 4.45 = 445 N

100 lbs. of force is equal to 445 Newtons.

### Step 2

Convert length to meters. To convert feet to meters (m), multiply by 0.3. For example, if length equals 2 feet:

2 * 0.3 = 0.6 meters

2 feet of length is equal to 0.6 meters.

### Step 3

Multiply force by length to calculate torque, which is measured in Newton meters (Nm):

445 * 0.6 = 267 Nm

References

Tips

- If you don't have a calculator handy, enter your formula into your computer's calculator or a Google search bar.

Things You'll Need

- Calculator or computer

Writer Bio

Ryan Menezes is a professional writer and blogger. He has a Bachelor of Science in journalism from Boston University and has written for the American Civil Liberties Union, the marketing firm InSegment and the project management service Assembla. He is also a member of Mensa and the American Parliamentary Debate Association.