MMA is a combat sport that, according to the Unified Rules put together in the 2000s, has 15 weight classes. However, the UFC is not obligated to include all of them, which is the reason why there are “only” 8 weight classes for men and 4 for female fighters.
Each UFC fighter competes in one division where they fight against opponents similar in weight and size, and they can also move up or down in weight to change the weight class.
Keep reading this article to learn more about UFC weight classes, and how this system works.
UFC Weight Classes (Divisions) Explained – Lbs, Kg, and St
The following are 8 UFC classes for men, and 4 for female fighters:
UFC men’s weight classes
| Weight class | Minimum Weight | Maximum Weight |
| Flyweight | 115lbs; 52.2kg; 8.2st | 125lbs; 56.7kg; 8.9st |
| Bantamweight | 125lbs; 56.7kg; 8.9st | 135lbs; 61.2kg; 9.6st |
| Featherweight | 135lbs; 61.2kg; 9.6st | 145lbs; 65.8kg; 10.3st |
| Lightweight | 145lbs; 65.8kg; 10.3st | 155lbs; 70.3kg; 11st |
| Welterweight | 155lbs; 70.3kg; 11st | 170lbs; 77.1kg; 12.1st |
| Middleweight | 170lbs; 77.1kg; 12.1st | 185lbs; 83.9kg; 13.2st |
| Light Heavyweight | 185lbs; 83.9kg; 13.2st | 205lbs; 93kg; 14.6st |
| Heavyweight | 205lbs; 93kg; 14.6st | 265lbs; 120.2kg; 18.9st |
UFC women’s weight classes
| Weight class | Minimum Weight | Maximum Weight |
| Strawweight | None | 115lbs; 52.2kg; 8.2st |
| Flyweight | 115lbs; 52.2kg; 8.2st | 125lbs; 56.7kg; 8.9st |
| Bantamweight | 125lbs; 56.7kg; 8.9st | 135lbs; 61.2kg; 9.6st |
| Featherweight | 135lbs; 61.2kg; 9.6st | 145lbs; 65.8kf; 10.3st |
When Did The UFC Add Weight Classes?
The UFC introduced the weight classes at UFC 12 event held in Dothan, Alabama in 1997. Initially, there were only two divisions:
- Lightweight — for fighters weighing below 200 pounds
- Heavyweight — for fighters weighing above 200 pounds.
Although this wasn’t an ideal solution, it was a starting point for the major changes that would come just a couple of years later.
The biggest change came in 2000 when the UFC started working with Athletic Commissions all across the US with the goal to regulate the sport. New Jersey State Athletic Commission was the first one to come up with the solution and set of rules named “Unified Rules of Mixed Martial Arts”.
Among many rules and changes, the biggest one was the birth of 15 weight classes. Bear in mind that the promotions do not have to implement all 15 divisions. This is why the UFC has 8 weight classes for men and 4 for women. But if they want, they can add more divisions whenever they want.
What Was UFC Open Weight Class?
Before the weight classes have emerged in 1997, the UFC events were open weight tournaments. Or in other words, there were no upper or lower weight limits meaning that fighters of any weight could compete.
When the UFC first started, UFC fighters often fought against much taller and heavier opponents which used to be very dangerous. But on the other side, this was normal back then as UFC events were promoted as legal street fighting venues where there were no rules or weight limits. It didn’t matter if a fighter weighs 170 or 500 pounds, the UFC allowed everyone to come in and compete under limited rules.
One such bizarre match saw a 200-pound karate expert Keith Hackney beating a 600-pound sumo wrestler Emmanuel Yarbrough at UFC 3. The other good example is Royce Gracie, arguably the most important figure in UFC history. He used to weigh around 175 pounds but his opponents would often be twice as big as he was.
The early years of UFC were simply too dangerous, and even barbaric in some way. The interest in the sport was there, but there was no way that this type of event would ever become legal in all states and worldwide. That’s why the UFC had decided to push for regulation, and make drastic changes in terms of rules in 1997 when they got rid of the open weight division.
Why Are There Weight Classes In UFC/MMA?
The purpose of weight classes is to make competition equal, fair, and safe. Within a weight class, all fighters are similar in weight, size, height, and neither fighter enjoys a big size advantage that can influence the outcome of the fight.
For instance, the former flyweight champ (125lbs), Demetrious Johnson used to be the pound for pound best fighter in the world for a long time. But what do you think would happen if there were no weight classes, with Johnson facing someone like Brock Lesnar who used to weigh over 265 pounds? Yes, Johnson might be more technical, talented, faster, but he would be mauled by Lesnar in a brutal fashion. As a result, in order to make the competition fair, different weight classes are created so that fighters can fight in the weight class that is closest to their natural weight and face opponents of similar sizes.
Each weight class in the UFC has a name, and minimum and maximum weight limits. For instance, the lower weight limit for the lightweight divisions is 145 pounds, while the upper limit is 155 pounds. A lightweight fighter must hit the scale within these limits on the official weigh-ins that are held around 24 hours before the event.
If it is a non-title bout, they are allowed to miss the upper limit by no more than 1 pound. In case it is a title bout, then both fighters must hit the scale at the upper limit or less. The process is the same for all other weight classes.
Back in the early days, UFC didn’t have weight limits which resulted in bizarre matchups where one fighter was twice as big as their opponent. Apart from the fact that this gives one fighter a big size advantage and with that better chances of winning, it is also very dangerous. Heavier fighters can generate more force in both striking and grappling, and hurt the smaller fighter much easier than vice versa.
Despite the weight limits, some fighters would still have a higher reach, be taller, or weigh more on fight night. But these differences are negligible compared to the times when there were no weight divisions.
Another reason is the UFC or any other MMA promotion must have weight classes in order to hold legal events. In the case they don’t, then the UFC would be banned in just about every US state, and with that, all across the world as well.
Are Boxing And UFC/MMA Weight Classes The Same?
No, the weight classes differ a lot between boxing and MMA, both when it comes to the number of divisions and weight limits. Here is a detailed table explanation:
| Weight Class | Boxing (Upper weight limit) | MMA (Upper weight limit) |
| Super Heavyweight | *only in amateur boxing | No Limit |
| Heavyweight | Unlimited | 265lbs; 120 kg |
| Cruiserweight | 200lbs; 90 kg | 225lbs; 102kg |
| Light heavyweight | 175lbs; 79kg | 205lbs; 93kg |
| Super middleweight | 168lbs; 76kg | 195lbs; 88.5kg |
| Middleweight | 160lbs; 72.5kg | 185lbs; 84kg |
| Super welterweight | 154lbs; 70kg | 175lbs; 79.5kg |
| Welterweight | 147lbs; 66.5kg | 170lbs; 77kg |
| Super lightweight | 140lbs ; 63.5kg | 165lbs ; 75kg |
| Lightweight | 135lbs ; 61kg | 155lbs ; 70kg |
| Super featherweight | 130lbs ; 59kg | / |
| Featherweight | 126lbs ; 57kg | 145lbs ; 66kg |
| Super bantamweight | 122lbs ; 55kg | / |
| Bantamweight | 118lbs ; 53.5kg | 135lbs ; 61kg |
| Super flyweight | 115lbs ; 52kg | / |
| Flyweight | 112lbs ; 51kg | 125lbs ; 56.5kg |
| Strawweight | / | 115lbs ; 52kg |
| Light flyweight | 108lbs ; 49kg | / |
| Minimumweight | 105lbs ; 48kg | / |
| Light minimumweight (Atom weight) | 102kg ; 46kg | 105lbs ; 48kg |
Can Fighters Switch Weight Classes In UFC?
Yes, UFC fighters are allowed to move up and down in weight to compete in different weight classes as long as they can meet the upper and lower weight limit for that specific weight class. Of course, they also do this as long as moving up or down makes sense in terms of their careers and performance. For example, UFC’s 170lbs champ Kamaru Usman can theoretically move up and fight in a 205lbs division but that won’t be a good idea in terms of his chances of winning.
There are many reasons why a fighter may change a weight class. One of the main reasons is the brutal weight cut and the impact this process has on their bodies. At some point in their career, a fighter no longer has the ability to cut so much weight without consequences, and this forces them to move a division up where they would cut less weight. One such fighter is Darren Till who used to struggle a lot with cutting down to 170lbs. At one point, he has decided to move up and compete in the 185lbs division.
On the other side, some fighters move down in weight because they feel they will have more success competing in the lower division against opponents similar or smaller in size.
Which UFC Weight Class Has The Most Number Of Fighters?
As of 2022, UFC’s lightweight division (155lbs; 70kg) has 111 active fighters, which is the most out of all weight classes. The second is welterweight (170lbs; 77kg) with 109 fighters on the roster. As for women’s weight classes, the strawweight division is in first place with 47 fighters, while the flyweight has 45 fighters.
Which UFC Weight Class Has The Most Knockouts?
UFC’s heavyweight division has always been associated with devastating knockouts, which the statistic is clearly confirming. Around 50% of all heavyweight matches end up in a KO, which is not a big surprise considering that just about every heavyweight has enough power to score a one-punch KO. In second place is the light heavyweight division where around 42% of fights end in a KO, followed by middleweight 35% and welterweight 32%.
Why Do UFC Fighters Cut Weight?
UFC fighters cut weight to compete in a weight class below their natural one. They do this to gain a physical advantage in height, weight, reach, and with that, in strength and power over the opponents. They lose up to 40 pounds in a week leading up to a fight and gain the majority of this weight back in less than 24 hours before the match starts.
But bear in mind that cutting a lot of weight is a modern practice done by just about every fighter in the UFC or other promotions. As long as the rules give fighters enough time to rehydrate and recover, they will keep cutting weight no matter what.
This means that, despite the brutal weight cut, fighters still end up competing against the opponent similar in size who did the same thing.
But this is not always the case as there have been few exceptions. For example, some fighters like Darren Till are capable of losing more weight than the others and get the advantage in size. Till used to fight in the 170-pound weight class where he was much bigger than his opponents. The other great example is Conor McGregor who used to cut all the way down to 145 pounds where he enjoyed a huge advantage in size and power.
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Why Do UFC Fighters Cut Weight So Late?
Most UFC fighters start cutting weight a couple of weeks before the event while they are still in the training camp. However, they lose the majority of the weight, between 20 and 40 pounds in a week leading up to a fight. They do this by extreme dehydration since getting rid of the water in your body is the only way you can lose so much weight within such a short time span. Upon recovering from the cut, the majority of weight they gain back is actually water.
They do this “late” or close to an event because you can’t pace dehydration and spread the process to a couple of weeks simply because that is not possible. Not getting enough fluid for weeks while still training hard is fraught with danger and would have an impact on your health.
What Happens When A UFC Fighter Misses Weight?
When a UFC fighter misses weight in their first attempt, the commission would give a fighter another 1 or 2 hours to lose extra pounds. In most cases, an hour or two is more than enough for a fighter to cut 0.5 or even up to 1 pound and pass the scale.
When a fighter misses weight in the second attempt, the UFC would ask their opponent to agree to a catchweight fight to save the fight. If the match was supposed to be at 155 pounds, the catchweight would be at around 160 or 165 pounds depending on the circumstances.
If the opponent agrees, which they do in most cases, the athletic commission overlooking the event needs to approve the fight (which they do most of the time) and the fight is on. A fighter who missed weight would forfeit between 20–30% of their fight purse and give it to their opponent who made weight and has agreed to a catchweight bout.
ADDITIONAL READING: What Happens When A UFC Fighter Misses Weight? Fully Explained
Do UFC Heavyweights Cut Weight?
Yes, throughout MMA history, there have been many UFC heavyweight fighters who needed to cut weight to meet the upper limit which is 265 pounds. One of the most famous heavyweights who used to cut weight was the former UFC champ and WWE start, Brock Lesnar who used to walk at around 280–290 pounds.
ADDITIONAL READING: Why Is There A Weight Limit For UFC Heavyweight Fighters? FAQ
Who Is The Heaviest UFC Fighter Ever Fought?
The heaviest UFC fighter ever was Emmanuel Yarbrough who fought during the early days of the promotion where there were no rules or weight classes. This giant was entering the cage weighing over 600 pounds to compete against fighters often twice as small as he was, like Keith Hackney who was weighing 200 pounds. Despite such a dramatic difference in weight, Hackney managed to beat Yarbrough at UFC 3.
Modern-day UFC has the upper weight limit for heavyweights, which is 265 pounds. But bear in mind that a lot of them cut weight to pass the scale and then gain the weight back before the fight starts. Or in other words, they weigh more than 265 pounds on fight night. Some of the heaviest are
- Brock Lesnar — around 280–285 pounds
- Derrick Lewis — close to 280 pounds or more
- Antonio Bigfoot Silva — 280–285 pounds
What Are Catchweights?
A catchweight in the UFC is the weight agreed upon by both fighters that do not adhere to the limits of the assigned weight divisions. For example, 155 lbs fighter and 170 lbs fighter may agree to fight at 165 lbs.
Make sure to read “What is Catchweight in UFC? Simply Explained.” This article explains everything you need to know about the UFC catchweight.
Conclusion
The main purpose of weight classes in UFC or any other combat sport is to level the playing field and make it safer. Having weight classes enable fighters to compete against opponents similar in weight and size and prevents fighters from having an unfair size advantage.