Enter the alternator power (W) and the alternator speed (RPM) into the Alternator Torque Calculator. The calculator will evaluate the Alternator Torque. 

Alternator Torque Formula

The following two example problems outline the steps and information needed to calculate the Alternator Torque.

AT = 9.5488 * P / S


  • AT is the Alternator Torque (N-m)
  • P is the alternator power (W) 
  • S is the alternator speed (RPM) 

To calculate the alternator torque, divided the power by the speed, then multiply by 9.5488.

How to Calculate Alternator Torque?

The following steps outline how to calculate the Alternator Torque.

  1. First, determine the alternator power (W). 
  2. Next, determine the alternator speed (RPM). 
  3. Next, gather the formula from above = AT = 9.5488 * P / S.
  4. Finally, calculate the Alternator Torque.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

alternator power (W) = 300

alternator speed (RPM) = 215

AT = 9.5488 * P / S = ?