What are the weight classes in MMA?
I · Intermediate · The fight · 1 of 5The unified rules list 15 weight classes, from atomweight at 105 pounds to super heavyweight above 265. The best known are flyweight at 125, bantamweight 135, featherweight 145, lightweight 155, welterweight 170, middleweight 185, light heavyweight 205 and heavyweight 265. A bout at an agreed weight outside those limits is a catchweight.
How it works
- Atomweight: up to 105 lb (about 47.6 kg).
- Strawweight: to 115 lb (52.2 kg).
- Flyweight: to 125 lb (56.7 kg).
- Bantamweight: to 135 lb (61.2 kg).
- Featherweight: to 145 lb (65.8 kg).
- Lightweight: to 155 lb (70.3 kg).
- Welterweight: to 170 lb (77.1 kg).
- Middleweight: to 185 lb (83.9 kg).
- Light heavyweight: to 205 lb (93 kg).
- Heavyweight: to 265 lb (120.2 kg).
- In between: super lightweight (165), super welterweight (175), super middleweight (195) and cruiserweight (225), with super heavyweight above 265.
- Same class: no limit on the gap between two fighters who both weigh in within the contracted class.
- Missed weight: if that puts the two in different classes, the heavier fighter may be no more than 5 lb above the lighter.
- Catchweight: an agreed weight. A commission may refuse the bout if the gap looks unsafe.
The glossary has the weight class, the catchweight, the weight cutting, the bout, the judges and the referee.
Tricky cases
A fighter weighs in a pound over a non-title limit. Is the fight off?
Not stated in the unified rules. The one-pound allowance often seen in non-title fights is a practice of commissions and promotions. The rules deal only with fighters who end up in different classes.
One fighter makes 155 and the other comes in at 158. Can they fight?
Yes, under the rules. The two are in different classes, and the heavier is within 5 lb of the lighter. Any penalty is a matter for the commission and the contract.
Is there a women's set of weight classes?
No. The list is one list. Which classes a promotion runs for women is its own choice.
How far ahead is the weigh-in?
Not stated in the unified rules. Each commission sets its own weigh-in procedure.
Why the rule exists
A heavier fighter hits harder and is harder to move, so fights are matched by weight. The five-pound limit after a missed weight stops a fighter from gaining a large advantage by failing to make the class. The commission's power to refuse a catchweight is a safety check.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Unified rules | 15 classes, in pounds | ABC Weight classes |
| Both inside the class | No allowance needed | ABC Weight classes a |
| Different classes after a miss | Gap of 5 lb at most | ABC Weight classes b |
| Contracted catchweight | No spread limit below the agreed weight | ABC Weight classes c |
| Kilogram figures | Converted for this page | R |
From the rule book
Association of Boxing Commissions and Combative Sports, Unified Rules of Mixed Martial Arts (as amended 23 July 2024; California State Athletic Commission copy), the weight classes table and its notes. Checked 14 October 2026. Official document: the association's Unified Rules of Mixed Martial Arts (adopted commission by commission).