Type in your bullet weight and your chrono readings. The power factor appears as you type, worked out the way the match will score it. That matters more than it sounds. Most power factor calculators multiply and divide and stop there. The rulebook then does two more things that decide whether you pass: it throws away the decimals, and if you fall short it re-shoots under rules that differ between USPSA and IPSC. This one does both, and it also tells you how much margin you’re carrying into a cold morning.