Click "Regular" To input every person's level and "Overall" To just do the two teams power level. You can click "Re-Calculate" To do it again with the same values.
I do fan-made Splatfests sometimes so I realized I needed a better way to determine the battle points because before it was just whoever had the most levels which isn't fair since a lot of people have lower levels but can still win the battle. So I made this and figured I could share it. It took 2 days, surprisingly since I messed up the calculations in the first and second draft. Like really bad. You could have 4 power total somehow and still have the same chance against someone with 100 power. Then in the second draft people with LOWER power had a better chance. But now it's fixed. But this honestly made me question my skill at math lol.