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MMA Weight Classes Explained: The Full List and What the Bands Really Mean

The complete unified-rules weight class table with pound limits, why the bands are uneven, and how catch weight and weight misses are handled.

Reign Creative Team6 min read

Key takeaways

  • The unified-rules table runs from Atomweight at 105 lbs up to Super Heavyweight above 265 lbs, and each named division is defined by an upper limit rather than a range you must sit inside.
  • The bands are deliberately uneven — 10 lbs through most of the middle, 5 lbs at welterweight and super welterweight, 20 at cruiserweight and 40 at heavyweight.
  • When a fighter misses weight and the two are in different classes, the rules cap the gap at five pounds; contracted catch weights carry no spread allowance at all.
  • Weight is a proxy for frame, reach and strength rather than a measure of skill, which is why a division limit does not tell you who wins a fight.
  • A fight simulator resolves bouts using its own model of ratings, styles and weight class, and produces nothing that predicts or describes real competition.

Weight classes exist for one reason, and it is not fairness in the sporting sense. It is that mass is an advantage no amount of skill reliably cancels, and a sport that lets any two people fight regardless of size is a sport that produces avoidable injuries.

Everything else about the system — the odd gaps between divisions, catch weight, the rules about missing weight — follows from that starting point.

Where the list actually comes from

There is a published table. The Unified Rules of Mixed Martial Arts, maintained by the Association of Boxing Commissions and Combative Sports, set out the divisions and their limits, and state regulators adopt them by reference — Nevada's administrative code for unarmed combat, for instance, points at the unified rules rather than restating them.

That is worth knowing because it means the weight classes are a matter of public record you can check yourself rather than something the sport agrees on informally. It also means promotions do not each invent their own; they select from the published set.

The full table

Weight class Limit
Atomweight up to and including 105 lbs
Straw Weight over 105 to 115 lbs
Flyweight over 115 to 125 lbs
Bantamweight over 125 to 135 lbs
Featherweight over 135 to 145 lbs
Lightweight over 145 to 155 lbs
Super Lightweight over 155 to 165 lbs
Welterweight over 165 to 170 lbs
Super Welterweight over 170 to 175 lbs
Middleweight over 175 to 185 lbs
Super Middleweight over 185 to 195 lbs
Light Heavyweight over 195 to 205 lbs
Cruiserweight over 205 to 225 lbs
Heavyweight over 225 to 265 lbs
Super Heavyweight over 265 lbs

Fifteen divisions. Not every promotion or commission runs all of them — the table is the menu of sanctioned divisions, not a claim about what is contested everywhere.

The bands are not the same size, and that is deliberate

Run the subtraction down the table and a pattern appears:

  • Most of the lower and middle divisions step in 10 lb increments: 115 to 125, 125 to 135, 135 to 145, and so on.
  • Welterweight (165 to 170) and Super Welterweight (170 to 175) are only 5 lbs wide each.
  • Cruiserweight spans 20 lbs (205 to 225).
  • Heavyweight spans 40 lbs (225 to 265).
  • Super Heavyweight has no upper bound at all.

Two forces produce that shape. The first is population: the middle of the table is where most competitors are, so finer divisions are possible and useful there. The second is proportion — five pounds is a meaningful fraction of a 135 lb fighter and a much smaller fraction of a 250 lb one, so equal-sized bands at the top would be splitting hairs while leaving divisions empty.

The practical consequence is that "same division" means very different things at different ends of the table. Two heavyweights can legally be forty pounds apart. Two welterweights cannot be more than five.

Allowances, catch weight and missing weight

Three provisions govern what happens when the neat table meets reality.

Within a division. If both fighters weigh in inside the same contracted division, the rules impose no allowance restrictions. They have both made the limit, and that is the end of the matter.

When somebody misses. If a fighter misses the contracted weight and the two competitors end up in different weight classes, the rules cap the difference: the heavier opponent shall not exceed five pounds over the lower-weighing fighter. That is the safety backstop, and it is why a badly missed weight can end a bout before it is made rather than merely costing a percentage of a purse.

Contracted catch weight. A catch weight bout is one agreed at a figure that is not a standard divisional limit. The rules state there is no weight spread allowance between contracted catch weight fighters so long as both are below the contracted weight, and they explicitly permit commissions to deny a catch weight bout where the differential looks like a safety problem.

Catch weight is often described as a compromise, and structurally that is exactly what it is: a negotiated number, with no division, no ranking and no title attached to it.

Why the number on the scale is a proxy, not a verdict

Weight is measured once, hours or a day before the fight, and what it is standing in for is frame — height, reach, limb length, muscle mass, the amount of force a body can generate and absorb.

Those things do not track weight perfectly. Two fighters who make the same limit can be built very differently, and the differences that matter in a fight are often the ones the scale does not see:

  • Reach. Where punches can land from, and whether one fighter can work outside the other's range.
  • Frame and leverage. Which matters enormously in the grappling exchanges where position is decided by leverage rather than by speed.
  • How the weight was made. A fighter who cut hard to make a limit and one who walks around near it arrive in different condition regardless of what the scale said.

This is also why a weight class does not settle anything. It equalises one variable so that the others — technique, style, conditioning, decision-making — are what decide the result. That is the whole point of having the table.

Weight class as a game mechanic

40-0 MMA & Boxing Fight Draft builds weight class into the drafting problem directly. You draft across eras and divisions, balancing ratings, records, eras and weight classes, and the simulators settle each bout on style, ratings and weight class rather than on ratings alone.

The genuinely interesting part is that the game models style advantage: power, defence, cardio, reach, grappling and fight IQ all feed the result, which means a stylistic edge can outweigh a ratings edge and the higher-rated fighter does not automatically get the nod. That is a defensible design choice, because it is roughly the thing weight classes exist to expose — once size is controlled for, matchups start deciding fights.

Bouts in the mixed martial arts simulator resolve by knockout, technical knockout, submission or decision, weighing striking, wrestling, takedowns, submissions and ground control. Boxing is simulated separately and adds draws and judges' scorecards, which the boxing scoring guide goes through in detail.

Around the drafting sit Unlimited Fight Draft, Limited Draft, Tournament, VS Computer, Draft Battle Royale and single-sport MMA and boxing drafts, plus a Fighter Explorer, collections, side-by-side comparisons, quizzes and daily challenges. GM Mode runs the business side — signing fighters, managing contracts and moving contenders toward title shots, with your decisions feeding the rankings.

What the simulation is and is not modelling

Worth stating plainly, because combat sports attract this confusion more than most.

The simulators take fictional fighters generated inside the game, apply the game's own internal rules about ratings, styles, divisions and matchups, and return a result. That result describes nothing outside the game. It is not a prediction, not a forecast, not analysis of any real athlete or event, and not guidance of any kind. It is a score on a roster-building puzzle.

The unbeaten record the game is named for is deliberately hard to reach, which is what makes a stable that falls short informative rather than disappointing. And no drafting approach guarantees it — a model with style advantages built in is a model where the obvious roster can lose.

Quick reference

  • Divisions are defined by an upper limit; the floor is simply the class below.
  • Band widths: mostly 10 lbs, 5 lbs at welterweight and super welterweight, 20 lbs at cruiserweight, 40 lbs at heavyweight, open above 265.
  • No allowance restrictions when both fighters make the same contracted division.
  • Five pounds maximum between fighters who end up in different classes after a missed weight.
  • No spread allowance for contracted catch weight fighters, and commissions may refuse the bout.
  • A professional round is five minutes with a one-minute rest; bouts run one to five rounds and cannot exceed five rounds or twenty-five minutes.

The companion piece to this one is how boxing scoring works, which covers the 10-point must system and what judges are told to look at. For the drafting side of combat sports specifically, see the MMA and boxing fight draft guide. If the management layer is what appeals, career mode versus franchise mode sets out how running a stable differs from playing as one competitor, and sports GM games without internet covers playing any of them on a flight.

Everything the studio makes in this genre is listed under sports GM.

Good to know

Frequently asked questions

What are the MMA weight classes?
The Unified Rules of Mixed Martial Arts published by the Association of Boxing Commissions list fifteen divisions, from Atomweight at up to and including 105 lbs through to Super Heavyweight for anyone above 265 lbs. Each named class is defined by its upper limit, with the lower bound simply being the class below it. Not every promotion or commission runs every division, so the published table is the full menu rather than a description of what is always contested.
Why are the weight bands different sizes?
They narrow where the sport is densest and widen where it is thinnest. Most of the middle of the table moves in 10 lb steps, but welterweight and super welterweight are only 5 lbs apart each, while cruiserweight spans 20 lbs and heavyweight spans 40. Wider bands at the top reflect the fact that there are fewer competitors there and that a fixed number of pounds matters proportionally less on a larger frame.
What is catch weight?
A bout contracted at a weight that is not one of the standard divisional limits. The unified rules state that there is no weight spread allowance between contracted catch weight fighters as long as both are below the contracted figure, and they allow commissions to refuse a catch weight bout if they judge the differential unsafe. It is a negotiated arrangement rather than a division, so it does not have a champion or a ranking of its own.
What happens if a fighter misses weight?
The unified rules address the situation where a fighter misses the contracted weight and the two competitors end up in different weight classes: the heavier opponent shall not exceed five pounds over the lower-weighing fighter. Within a single contracted division there are no allowance restrictions, because both fighters have already made the same limit. Individual commissions and promotions layer their own consequences on top, which are set by contract rather than by the unified rules.
How long is an MMA fight?
Under the unified rules a professional round lasts five minutes with a one-minute rest between rounds, and bouts may be scheduled for one, two, three, four or five rounds. No contest may exceed five rounds or twenty-five minutes, which is the same thing since five rounds of five minutes is twenty-five minutes of fighting. The rules also state that no contestant may exceed five rounds or twenty-five minutes of fighting within any twenty-four hour period.
Do fight draft games use real fighters and promotions?
No. 40-0 MMA & Boxing Fight Draft is a fictional simulation and is not affiliated with, endorsed by or connected to any real promotion, sanctioning body, event or athlete. Weight classes appear in it as a game mechanic that shapes matchups, and the results it produces are outputs of its own model rather than statements about anybody real.

Sources

  1. Unified Rules of Mixed Martial Arts (August 2025) (opens in a new tab)Association of Boxing Commissions and Combative Sports — accessed
  2. Unified Rules (opens in a new tab)Association of Boxing Commissions and Combative Sports — accessed
  3. Nevada Administrative Code Chapter 467: Unarmed Combat (opens in a new tab)Nevada Legislature — accessed

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