There are eight traditional classes in mainstream MMA boxing, running from flyweight to heavyweight. However, there are occasionally fights that are held in the intermediate classes between the regulation eight, with the super heavyweight division sometimes used for the very heaviest athletes.
There are some discrepancies in the terminology used by various American and world organisations, but for the most part, UFC and Bellator lead the way on the standard descriptions and classes.
One quirk of some MMA organisations, including UFC, is that there is an extra lb's grace for fights where a title is not at stake. That means that a lightweight title fight has its limit at 155lbs, but for other fights the athletes will have to come in at or under 156lbs.
We’ve highlighted the non-title limits in bold, below, with the title requirements coming in first.
Flyweight
Weight limit: 125lb/126lb
The UFC uses the 116lb-125lb class as its flyweight,with strawweight sitting below that, in a rarely used class.
Bantamweight
Weight limit: 135lb/136lb
Most mainstream MMA companies operate at 126lb-135lb for bantamweight, while the King of the Cage calls this weight the flyweight class.
Featherweight
Weight limit: 145lb/146lb
The featherweight division is generally regarded in mainstream MMA organisations as between 136lbs and 145lbs. However, King of the Cage uses the term bantamweight to describe this class.
Lightweight
Weight limit: 155lb/156lb
The lightweight division is set between 146lbs and 155lbs in mainstream US MMA organisations. It dropped out of use in UFC around 2004 but was reinstated in 2006 at UFC 58.
Welterweight
Weight limit: 170lb/171lb
The welterweight division represents a number of weights in MMA. For the UFC, it is 156lbs to 170lbs, but ONE Championship set its upper weight limit at 185.2lbs. It is further clouded by the traditional boxing welterweight class of a 147lbs limit.
Middleweight
Weight limit: 185lb/186lb
For the UFC, the middleweight division is for fighters between 171 to 185lbs, and there is variation across other organisations, but the UFC’s position is the consensus framework.
Light heavyweight
Weight limit: 205lb/206lb
The light heavyweight division for UFC is between 186lbs and 205lbs, matching most other major organisations.
Heavyweight
Weight limit: 265lb/266lb
The heavyweight division is generally accepted as the upper limit for regular fights in mixed martial arts. Both the UFC and Bellator recognise the division for fighters between 206-265lbs, making it the division with the widest stated scope.
Super heavyweight
Weight limit: N/A
The super heavyweight division is used to accommodate fighters above 265lb, though it is rarely used by the mainstream organisations. The UFC have on occasion put on super heavyweight fights.