Weight classes and weigh-ins compared
The number on the chart is only half the story. When you weigh in, and what you wear on the scale, decide how much room you have to cut and how much time you have to refuel. Here is how each sport we cover handles it, taken from each governing body's own rules.
| Sport | Classes | When you weigh in | On the scale |
|---|---|---|---|
| UFC | 9 UFC divisions, 15 under the Unified Rules | Day before, 9 to 11 am | 1 lb allowance in non-title bouts |
| PFL | 8 ranked divisions | Day before | Missing weight can cost part of the purse |
| Pro boxing | 17 (WBC adds Bridgerweight) | IBF: 20 to 30 hours before, plus a fight-day check | IBF fight-day limit is 10 to 14 lb over the class |
| Muay Thai | IFMA amateur and WBC Muaythai pro | IFMA: each morning; WBC: 24 to 30 hours before | IFMA: 5% over before a bout means disqualification |
| IBJJF jiu-jitsu | 9 men, 8 women, gi and no-gi | Right before your first match | In your gi or no-gi uniform, once only |
| Judo | 7 men, 7 women, plus open | Day before at 16:00, plus a random check on fight day | Underwear; random check allows 5% over |
| NCAA wrestling | 10 men, 10 women | 2 hours or less before competing | 1 lb allowance for back-to-back days |
| High school wrestling | 12, 13 or 14 per state, boys and girls | Set by your state | Certified minimum weight; growth allowance set by state |
Why the weigh-in time matters
A day-before weigh-in, like the UFC or judo, leaves a night to eat and drink again. A weigh-in a couple of hours before you compete, like college wrestling or IBJJF, leaves almost no time, so you need to be close to your class already. A fight-day check, like the IBF second weigh-in or the judo random weigh-in, caps how far you can drift above your class after the official scale.
That is why the safest class is usually the one you can make while still eating and training normally. Each page above lists the limits in pounds and kilograms, links the official rule book, and explains what happens if you miss.
Plan the cut, not just the class
Once you know your class, the weight cut calculator shows how far you are from it and how long a steady drop takes, and the weigh-in countdown turns the date into a daily target. The rehydration calculator covers the hours after the scale. For wrestlers, the full wrestling guide walks through the season rule by rule.