Calculating power factor before a match ensures that all competitive shooter are on a somewhat level playing field when they go to compete. Most competitive shooting disciplines categorize calibers into 2 main categories: Major and Minor. Major calibers are typically larger calibers like 40 and 45 while 9mm typically fits the minor category. 9mm can be loaded in a way that allows it to qualify for the major category, but we won't delve into that here. When calculating power factor, it's important to recognize that the length of your barrel will impact your ammo's velocity. Most manufacturers give you a published velocity on the box but don't say squat about whether the round was tested from a PCC or a snubby to achieve that velocity. Though we do publish our test barrel length on every box, we strongly encourage you to chronograph your ammo out of your gun to get the most accurate data you can before competing.

Here's the calculator for your reference:  

USPSA Requirements:

 Handgun Major 165
Handgun Minor 125
Rifle Major 320
Rifle Minor 150


IDPA Requirements:

Customer Defensive Pistol 165
Stock Service Pistol 125
Compact Carry Pistol 125
Enhanced Revolver 155
Stock Revolver 105
Back Up Gun 95