The UFC has come a long way since it was originally a one night no-holds barred anything goes tournament. To survive, the UFC had to make MMA a legitimate sport.

Along with a clear set of rules, the UFC needed another important thing to legitimize MMA. Weight classes.

For those that are new fans to MMA, you may be wondering how they came up with their weight classes. This write-up is a complete history of the UFC weight classes explained.

We’ll start by detailing when weight classes were first implemented into the promotion. Along with that, we’ll give you a short history of each weight class. Including when they were brought in and list the champions of each division

Why were weight classes added?

UFC weight classes were added for a number of different reasons. One of the main reasons why UFC weight classes were added is because they needed to be added to legitimize the sport.

If they were going to become more respected and add more fans, they needed to make weight divisions. They could no longer continue having no rules brawls between a massive heavyweight against a lightweight fighter.

Then as MMA grew, the fighters started to become more well-rounded. This meant that the UFC had to even the playing field and have fighters go against opponents closer to their weight.

Doing this improved the product drastically as we saw more exciting fights and star athletes emerge. Without gradually adding weight classes, MMA would not be the sport it is today.

When were UFC weight classes added?

The UFC began adding weight classes in 1997, which was only 4 years after the promotion started. 

They would add two weight classes to their UFC 12 tournaments. Heavyweight, which was 200lbs(90.71Kgs) and lightweight at 199lbs(90.2Kgs) and below.

After this tournament, the UFC would continue to gradually add more weight classes. At UFC 14, the lightweight category would be rebranded the middleweight division,

Then at UFC 16, a lightweight division was added at 170lbs(77Kgs) and below. Later renamed the welterweight division as we know it now.

For a while, the UFC would keep it to just these 3 divisions and the results were a success. Fight fans saw the emergence of many talented fighters and higher level fights.

When they reached UFC 26, a bantamweight division of 155lbs(70Kgs) was added to the promotion.

UFC weight classes shake up

After the introduction of the original bantamweight class at 155lbs was added, they reorganized the UFC weight classes.

Jens Pulver would win the inaugural UFC Bantamweight Championship, which was renamed the UFC Lightweight division. Subsequently, the 170lb division would be renamed the welterweight division and be from 156lbs to 170lbs.

The middleweight division would stay, but a light heavyweight division was added at 205lbs(93Kgs).

Bantamweight and featherweight

More divisions wouldn’t be added until 2010, when the Zuffa owned WEC merged into the UFC. Initially, the WEC was made to showcase smaller weight classes, but they got popular and so they merged.

With the merger, we saw the addition of the featherweight division at 145lbs(66Kgs) and the bantamweight division(61Kgs).

A year later, the promotion added a flyweight division at 125lbs(57Kgs) with the first fight taking place in 2012.

UFC adds a women’s divisions

The UFC would buy rival company Strikeforce and with that purchase, they added the first female division.

Initially the first women’s division was the women’s bantamweight division with the first fight taking place in 2013. Then in 2014, a UFC strawweight division was added for women at 115lbs (52Kgs). 

Later a flyweight division was established and the last to be added was a women’s featherweight division.

How many UFC weight classes are there today?

Today in the modern era of MMA, the UFC currently there is 12 UFC weight classes between the men and women fighters. 8 men’s UFC weight classes and 4 women’s UFC weight classes.

The UFC weight classes in order

Men’s weight classes

UFC Weight Class (Mens)Weight In LbWeight In Kg
Strawweight115 lb52.5 kg
Flyweight125 lb56.7 kg
Bantamweight135 lb61.2 kg
Featherweight145 lb65.8 kg
Lightweight155 lb70.3 kg
Welterweight170 lb77.1 kg
Middleweight185 lb83.9 kg
Light Heavyweight205 lb102.1 kg
Heavyweight265 lb120.2 kg

Women’s weight classes

UFC Weight Classes (Womens)Weight In LbWeight In Kg
Strawweight115 lb52.5 kg
Flyweight125 lb56.7 kg
Bantamweight135 lb61.2 kg

UFC women’s weight classes

The women’s divisions in the UFC are a bit different than the men’s divisions and you may wonder why? There are actually two specific reasons why the women’s weight classes look the way they are.

  • Genetics: Human females males are generally smaller than human males. So women’s MMA divisions would naturally be put at lower weights than half the men’s divisions.
  • Smaller Talent Pool: Along with being smaller than men, there is just a smaller talent pool of women that train in MMA. Which is why there are less women’s divisions than men’s divisions.

The guidelines of UFC weight classes

The weight classes within the MMA and not just MMA have specific rules and guidelines. These guidelines and rules for weight classes are explained within the Unified Rules of Mixed Martial Arts.

UFC weight class limits

Weight class limits were set in place, to separate fighters by size and make fights more competitive. Fighters who fight at heavyweight are legally not allowed to fight anyone below their weight class. So you will never see a flyweight fighter fight a heavyweight fighter

Each weight class is placed at a specific weight, but fighters don’t have to come in at exactly that weight. Fighters are allowed to come in up to 1 pound over the weight limit or a certain  number of pounds under the limit.

For example, if you are fighting in the UFC welterweight division, your target weight is 170lbs. That means you can either come in one pound over at 171lbs or under at around 160-169lbs.

UFC weight class rules for title fights

The weight class rules for title fights are more strict than the rules for a non title bout. In a UFC title bout, fighters are not given an extra pound above the designated weight.

They must come in at either the designated weight or under the weight for the title bout to be for the title. If a fighter misses weight in a title fight, the fight is no longer for the title.

What happens when a fighter misses weight?

Whenever a fighter misses weight, they are given one hour to lose the extra weight. They will continue the process of cutting weight for one hour before stepping on the scale again.

If they weigh in again on weight, the fight is on with no penalty. But if they miss weight, they go through a different process depending on how many pounds they missed by.

When a fighter misses weight by a small amount, the fight goes on and they are penalized a percentage of their fight purse. If they miss weight by more than 5 pounds, that poses a bigger problem.

Usually it is left up to the offending fighter’s opponent to take the fight or not. If their opponent accepts, the fight is on and the offending fighter is deducted a percentage of their fight purse.

In other cases where fighters miss weight by over 10lbs, most athletic commissions will cancel the fight altogether.

Catchweight fights

Catchweight fights are matches that take place in between the designated UFC weight divisions. UFC bouts where both fighters miss weight, but agree to fight are also considered catchweight fights.

The most notable catchweight fight to happen in the UFC was Nate Diaz vs Jorge Masvidal at UFC 244. They fought for the inaugural BAMF championship that was created for that match.

Will there be more UFC weight classes?

Despite calls for more UFC weight classes by many fighters and critics, there are no current plans to add new divisions. A women’s atomweight division at 105lbs has been discussed before, but has yet to be implemented.

If UFC commentator Joe Rogan had it his way, there would be UFC divisions at every 10lb increment. Going from 150lbs, 160lbs, 170lbs, etc.

Timeline of division champions

Let’s look at the timeline of champions within each UFC weight class who have risen through the UFC rankings, including current champions holding the belt. Here is a complete list of each champion from when the division started.

Heavyweight division 265 lb (120.2 kg)

The heavyweight division was the first official weight class of the UFC. Initially, it was 200lbs and up, but moved up to 206lbs-265lbs after the introduction of the light heavyweight division. Here is the list of the 22 undisputed UFC heavyweight champions since 1997.

Interim champions: Andrei Arlovski, Antonio Minotauro Nogueira, Frank Mir, Shane Carwin, Fabricio Werdum, Cyril Gane

Light Heavyweight division 205 lb (102.1 kg)

Initially, the light heavyweight division was the middleweight division and went from 186 to 205lbs(84-93kg). It was later changed to just 205lbs as of May 4, 2001 at UFC 31. Here are the 15 undisputed UFC light heavyweight champions in the division’s history.

Interim champions: Randy Couture, Jon Jones

Middleweight Division 185 lb (83.9 kg)

The middleweight division was introduced the same time as the light heavyweight division in 2001. The division goes from 171lbs to 185lbs(78 to 84kg) and there have been 11 undisputed UFC Middleweight Champions. Here is the complete list.

Interim champions: Robert Whitaker, Israel Adesanya

Welterweight division 170 lb (77.1 kg)

Originally known as the lightweight division, it was renamed the welterweight division in 2001. In it’s 20 year history there have been 12 undisputed welterweight champions. Here is the complete list.

Interim Champions: Georges St Pierre, Carlos Condit, Colby Covington

Lightweight Division 155 lb (70.3 kg)

Originally named the bantamweight UFC weight class, the lightweight division was implemented in 2001. There have been 11 undisputed UFC lightweight champions and here is the complete list.

  • Jens Pulver

(The division was disbanded in 2001 and didn’t return until 2006)

Interim Champions: Tony Ferguson, Dustin Poirier, Justin Gaethje

Featherweight division 145 lb (65.8 kg)

With the UFC merger in 2010, the WEC featherweight division became the UFC featherweight division. In its 11 year history there have been 5 undisputed UFC featherweight champions and here is the complete list.

  • Jose Aldo
  • Conor McGregor
  • Jose Aldo
  • Max Holloway
  • Alex Volkanovski

Interim Champions: Conor McGregor, Jose Aldo, Max Holloway

Bantamweight division 135 lb (61.2 kg)

The UFC bantamweight division was introduced during the WEC merger. There have been 9 undisputed UFC bantamweight champions in the division’s history and are as follows. 

  • Dominick Cruz
  • Renan Barao
  • TJ Dillashaw
  • Dominick Cruz
  • Cody Garbrandt
  • TJ Dillashaw
  • Henry Cejudo
  • Peter Yan
  • Aljamain Sterling

Interim Champions: Renan Barao

Flyweight division 125 lb (56.7 kg)

The UFC flyweight was introduced in 2012 ranging from 116 to 125lbs(53 to 57kgs). In the 9 year history of the division, there have been 4 undisputed UFC flyweight champions and are as follows.

Interim Champions: 0

Women’s featherweight division

The UFC women’s featherweight division was established 10 months before the women’s flyweight division was introduced. It was established in 2017 and there have been 3 undisputed UFC women’s featherweight champions.

Interim Champions: 0

Women’s Bantamweight division

With the purchase of Strikeforce, the UFC started the women’s bantamweight division. The first fight took place in 2012 and there have been 4 undisputed UFC women’s bantamweight champions.

Interim Champions: 0

Women’s flyweight division

The UFC women’s flyweight division was the last division added to the UFC as of December 1st, 2017. Since then there have only been a total of just 2 undisputed UFC women’s flyweight champions.

Interim Champions: 0

Women’s strawweight division

The UFC women’s strawweight division was established in 2014 with the inaugural title decided on that year’s The Ultimate Fighter season. Since the division was introduced there have been 6 undisputed UFC strawweight champions.

  • Carla Esparza
  • Joanna Champion
  • Rose Namajunas
  • Jessica Andrade
  • Zhang Weili
  • Rose Namajunas

Interim Champions: 0