Enter the bullet weight (grains) and the velocity (fps) into the Power Factor Calculator. The calculator will evaluate the Power Factor. 

Power Factor Formula

The following two example problems outline the steps and information needed to calculate the Power Factor.

PF = W * V / 1000


  • PF is the Power Factor ((gr-fps))
  • W is the bullet weight (grains) 
  • V is the velocity (fps) 

How to Calculate Power Factor?

The following steps outline how to calculate the Power Factor.

  1. First, determine the bullet weight (grains). 
  2. Next, determine the velocity (fps). 
  3. Next, gather the formula from above = PF = W * V / 1000.
  4. Finally, calculate the Power Factor.
  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.

the bullet weight (grains) = 125

velocity (fps) = 1000

PF = W * V / 1000 = ?