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Complete Guide to Muay Thai Weight Classes and Divisions


In the ancient era, nobody cared about weight divisions. Two fighters were fighting toe-to-toe until one of them was unable to continue the bout.

But Thai boxing is nowadays a sport with a clear ruleset. Muay Thai weight classes and divisions exist for a reason.

How do officials check fighter’s class? Is the weigh-in happening on the day of the fight or one day before? If you don’t wanna get caught missing weight, please read more about Muay Thai weight classes and divisions.

Why Do Weight Classes Exist?

The answer to this question is very simple. Physics class, elementary school. Let me clarify Newton’s Second Law of Motion to you.

Muay Thai Weight Classes and Divisions

F (force) = M (mass) x A (acceleration)

This means a heavier fighter (more lean mass or just fat) hits harder for the same speed of impact.

Let me give you an example. When a heavyweight and atomweight fighter hit the heavy bag, of course, a big massive dude will hit harder, even though both of them are martial art masters. Why? The answer is so simple – greater mass leads to more powerful strikes.

Weight classes & divisions exist primarily due to fighters’ safety. You can’t pair a welterweight with a middleweight because he’d get hurt badly, plus it’d be a huge mismatch.

Even one pound can make a critical difference between two athletes in their primes (especially smaller weight classes).

Just to know, different promotions offer different weight classes. My advice is to read the invitation letter thoroughly or to check the divisions before the competition with a promoter. A weigh-in miss means you’ll probably go one division up (or disqualification, depending on the tournament rules). It leads to facing stronger opponents and a greater possibility of getting hurt or knocked out.

Muay Thai Weight Classes and Divisions – Differences Between Promotions

Before we start, all the weights are in pounds. If you want to transform pounds to kilograms, please divide the number by 2.205 (one kilogram equals 2.205 pounds, for example, 175 / 2.205 = 79,387 kg).

Note: in some competitions, you are allowed to weigh a bit more (for example, if the limit is 175 pounds, the tolerance might be +0.5 pounds, but please check with the tournament promoter).

WBC Muay Thai (World Boxing Council) + Elite Stadiums

Here is the list of weight classes in use at elite stadiums of Thailand (e.g. Lumpinee, Rajadamnern, etc.) and the WBC Muay Thai (World Boxing Council):

Muay Thai Weight Classes & Divisions NamesPounds
Mini Flyweight100 – 105 lbs
Junior Flyweight105 – 108 lbs
Flyweight108 – 112 lbs
Junior Bantamweight112 – 115 lbs
Bantamweight115 – 118 lbs
Junior Featherweight118 – 122 lbs
Featherweight122 – 126 lbs
Junior Lightweight126 – 130 lbs
Lightweight130 – 135 lbs
Junior Welterweight135 – 140 lbs
Welterweight140 – 147 lbs
Junior Middleweight147 – 156 lbs
Middleweight156 – 160 lbs
Junior Heavyweight160 – 175 lbs
Heavyweight175 lbs

World Professional Muay Thai Federation (WPMF)

As well as you see, the World Professional Muay Thai Federation (WPMF) adopted different weight classes.

Muay Thai Weight Classes & Divisions NamesPounds
Pin Weight103 lbs
Mini Flyweight106 lbs
Light Flyweight109 lbs
Flyweight112 lbs
Super Flyweight115 lbs
Bantamweight118 lbs
Super Bantamweight122 lbs
Featherweight126 lbs
Super Featherweight130 lbs
Lightweight135 lbs
Super Lightweight140 lbs
Welterweight147 lbs
Super Welterweight154 lbs
Middleweight161 lbs
Super Middleweight168 lbs
Cruiserweight175 lbs
Super Cruiserweight190 lbs
Heavyweight210 lbs
Super Heavyweight265 lbs

World Thai Boxing Association (Junior, Amateur, and Adult)

World Thai Boxing Association offers different weight classes too. So before you go to the competition, check the invitation at least two or three times.

Muay Thai Weight Classes & Divisions NamesPounds
Junior Pin Weight47 lbs
Junior Atomweight52 lbs
Junior Strawweight57 lbs
Junior Flyweight62 lbs
Junior Bantamweight67 lbs
Junior Featherweight72 lbs
Junior Lightweight77 lbs
Junior Welterweight82 lbs
Junior Middleweight87 lbs
Junior Cruiserweight92 lbs
Junior Heavyweight+97 lbs
Welterweight147 lbs
Super Welterweight154 lbs
Middleweight161 lbs
Super Middleweight168 lbs
Cruiserweight175 lbs
Super Cruiserweight190 lbs
Heavyweight210 lbs
Super Heavyweight265 lbs
Girls/Boys Pin Weight102 lbs
Girls/Boys Atomweight107 lbs
Girls/Boys Strawweight112 lbs
Girls/Boys Flyweight117 lbs
Girls/Boys Bantamweight122 lbs
Girls/Boys Featherweight127 lbs
Girls/Boys Lightweight132 lbs
Girls/Boys Super Lightweight137 lbs
Girls/Boys Light Welterweight142 lbs
Girls/Boys Welterweight147 lbs
Girls/Boys Super Welterweight153 lbs
Girls/Boys Light Middleweight159 lbs
Girls/Boys Middleweight165 lbs
Girls/Boys Super Middleweight172 lbs
Girls/Boys Light Heavyweight179 lbs
Girls/Boys Light Cruiserweight186 lbs
Girls/Boys Cruiserweight195 lbs
Girls/Boys Heavyweight215 lbs
Girls/Boys Super Heavyweight+215 lbs
Pin weight102 lbs
Atomweight107 lbs
Strawweight112 lbs
Flyweight117 lbs
Bantamweight122 lbs
Featherweight127 lbs
Lightweight132 lbs
Super Lightweight137 lbs
Light Welterweight142 lbs
Welterweight147 lbs
Super Welterweight153 lbs
Light Middleweight159 lbs
Middleweight165 lbs
Super Middleweight172 lbs
Light Heavyweight179 lbs
Light Cruiserweight186 lbs
Cruiserweight195 lbs
Heavyweight215 lbs
Super Heavyweight+215 lbs

Cutting Weight

In Muay Thai, every single pound matters. When two fighters are evenly matched, a stronger strike might make the difference and leave a better impression on judges. But how do fighters cut weight and how many pounds are considered “safe”? Please read on, I will explain it to you.

weight cutting

Many fighters go to the sauna or hot tube daily, one week before the fight, draining their bodies and reducing 10-15 pounds (some even cut more, but this is considered dangerous). Also, some ring warriors cut their rations a week or two before the fight. For example, despite somebody’s walking weight is 160 lbs, he can easily drop to around 140 lbs without endangering his health. But why do fighters do it?

In any martial art, extra pounds mean a lot. The weigh-in sometimes happens a day before the fight, which lets a fighter recover from a harsh weight loss. So a fighter who competes at 140 lbs (just an example) could weigh 155+ pounds on the day of the fight. So it is more than obvious that Muay Thai weight classes and divisions are not based on fighters’ walking weight.

Let me give you an example from the MMA world. Paulo Costa, the former UFC Middleweight title contender, weighed around 210-215 pounds for his 185-pound title fight versus Israel Adesanya on the day of the match. Ring warriors usually target “minimum weight that won’t endanger health”.

But some promotions insist on “fighting on walking weight” and control ring warriors one week ahead of the bout because of previous bad experiences. Famous MMA promotion ONE FC is a good example, they changed the policy after the death of Chinese flyweight fighter Yang Jian Bing, whose body was unable to handle massive weight loss in 2015.

There is no strict rule that bonds Muay Thai weight classes and divisions and walking weight yet, but it might change in the years to come.

Openweight And Fighting Above The Optimal Weight

Listen, pairing fighters from different Muay Thai weight classes and divisions can happen in an Openweight competition, and you might see it from time to time in some tournaments. Elite level competitors are sometimes ready to go up or accept challenges against heavier opponents.

Is fighting stronger and heavier foe allowed? Well, yes and no, it depends on a tournament. My advice – ask the promoter.

For example, Kaoklai Kaennorsing was known for fighting bigger opponents, but you need the heart of a lion and an insane level of bravery. Despite Kaoklai weighed only 172 lbs, he took part in Openweight battles with Heavyweight fighters.

The Thai fighter turned the lights out on Mighty Moe, who weighed 273 lbs the day of the fight! Moe was trying to march forward, but Kaoklai’s reaction time and footwork were out of this world. A fabulous right high kick counter stopped Moe’s weaving overhand right attempt.

Kaoklai also fought other famous heavyweight ring warriors at K-1 tournaments – Ray Sefo, Park Yong Soo, Hong Man Choi, Alexey Ignasov, Musashi, Mike Bernardo, Tsuyoshi Nakasako… He is the youngest and lightest fighter to win a K-1 Openweight tournament (2004).

Another elite-level Thai warrior, famous for knocking out heavier opponents, is Saenchai, a master of switch kick and scissor kick. Fighting 10 or 20 pounds heavier foes was a piece of cake for this fabulous Muay Thai legend.


I hope you got a clearer insight into Muay Thai weight classes and divisions after reading this article. I kindly recommend you to talk to promoters and read the invitation letters thoroughly. Surprises might affect your performance in the competition, get ready before the fight!

Please don’t forget, a few extra pounds might give you an advantage when you’re dealing evenly matched foe!

Last Updated on May 21, 2022 by Deni

Picture of Deni


Hi, I started training Muay Thai back in 2016 and fell in love with it. So I decided to create this blog in the pursuit of this passion and share my experience with you.

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