Weight Classes
MMA weight classes are not uniform across promotions. ONE Championship uses kilograms and hydration-tested cuts, the UFC defines its divisions in pounds with same-day weigh-ins, and PFL reorganized the bantamweight and heavyweight tiers for its league format. Use this table to cross-reference contracted limits.
| Class | UFC (lbs) | ONE (kg) | Bellator (lbs) | PFL (lbs) |
|---|---|---|---|---|
| Atomweight (Women) | — | 52.2 | — | 115 |
| Strawweight (Women) | 115 | 56.7 | — | — |
| Flyweight | 125 | 61.2 | 125 | 125 |
| Bantamweight | 135 | 65.8 | 135 | — |
| Featherweight | 145 | 70.3 | 145 | 145 |
| Lightweight | 155 | 77.1 | 155 | 155 |
| Welterweight | 170 | 83.9 | 170 | 170 |
| Middleweight | 185 | 92.9 | 185 | — |
| Light Heavyweight | 205 | 102.1 | 205 | 205 |
| Heavyweight | 265 | 120.2 | 265 | 265 |
Why the discrepancies matter
ONE Championship's hydration testing means a fighter contracted at 70.3 kg (155 lbs) can only step on the scale 0.5 kg above contract weight 24 hours before the fight and must pass a urine specific-gravity test for hydration. The result is fighters competing much closer to their walking weight — a ONE lightweight is often the same physical size as a UFC welterweight.
The UFC uses same-day weigh-ins (technically morning-of) with no hydration testing. Fighters routinely cut 20-30 lbs in the final 24 hours and rehydrate to 15-20 lbs above contract by fight time. The lightweight division has historically housed athletes who walk around at 180-185 lbs.
PFL added a women's lightweight bracket (155 lbs) and eliminated some men's divisions to suit its season + playoffs format. The minimum roster size per division dictates which weight classes get a tournament in a given season.
Bellator's divisions broadly mirror the UFC's, including a 165 lbs catchweight that was floated for years as a possible "super lightweight" division without ever being formalized as a title belt.