Old Doctor's Scale

Muay Thai Weight Classes & Divisions

There are many different muay thai fight promotions with slightly different weight classes in pounds and kilos. Here is a compiled list of the weight classes for major organizations, so you don’t get caught missing weight. These classes are used at international promotions from Thailand to the USA, UK, Europe, Canada, and Australia and apply to female and male athletes.

Weight Divisions by Thai Boxing Organization

World Boxing Council (WBC) Muaythai

Mini Flyweight105 lb (47.627 kg)
Light Flyweight108 lb (48.988 kg)
Flyweight112 lb (50.802 kg)
Super Flyweight115 lb (52.163 kg)
Bantamweight118 lb (53.524 kg)
Super Bantamweight122 lb (55.338 kg)
Featherweight126 lb (57.153 kg)
Super Featherweight130 lb (58.967 kg)
Lightweight135 lb (61.235 kg)
Super Lightweight140 lb (63.503 kg)
Welterweight147 lb (66.678 kg)
Super Welterweight154 lb (69.853 kg)
Middleweight160 lb (72.575 kg)
Super Middleweight168 lb (76.204 kg)
Light Heavyweight175 lb (79.379 kg)
Cruiserweight190 lb (86.183 kg)
Super Cruiserweight210 lb (95.254 kg)
Heavyweight230 lb (104.326 kg)

World Professional Muay Thai Federation (WPMF)

Pinweight103 lb (46.720 kg)
Mini Flyweight106 lb (48.081 kg)
Light Flyweight109 lb (49.442 kg)
Flyweight112 lb (50.802 kg)
Super Flyweight115 lb (52.163 kg)
Bantamweight118 lb (53.524 kg)
Super Bantamweight122 lb (55.338 kg)
Featherweight126 lb (57.153 kg)
Super Featherweight130 lb (58.967 kg)
Lightweight135 lb (61.235 kg)
Super Lightweight140 lb (63.503 kg)
Welterweight147 lb (66.678 kg)
Super Welterweight154 lb (69.853 kg)
Middleweight161 lb (73.028 kg)
Super Middleweight168 lb (76.204 kg)
Cruiserweight175 lb (79.379 kg)
Super Cruiserweight190 lb (86.183 kg)
Heavyweight210 lb (95.254 kg)
Super Heavyweight265 lb (120.202 kg)

International Kickboxing Federation (IKF)

Mini Flyweight105 lb (47.62 kg)
Junior Flyweight108 lb (48.99 kg)
Flyweight111 lb (50.35 kg)
Junior Bantamweight114 lb (51.71 kg)
Bantamweight118 lb (53.52 kg)
Junior Featherweight122 lb (55.34 kg)
Featherweight126 lb (57.15 kg)
Junior Lightweight130 lb (58.97 kg)
Lightweight135 lb (61.24 kg)
Junior Welterweight140 lb (63.5 kg)
Welterweight147 lb (66.68 kg)
Junior Middleweight154 lb (69.85 kg)
Middleweight161 lb (73.03 kg)
Super Middleweight168 lb (>76.2 kg)
Light Heavyweight175 lb (79.38 kg)
Super Light Heavyweight182 lb (82.55 kg)
Cruiserweight190 lb (86.18 kg)
Heavyweight210 lb (95.3 kg)
Super HeavyweightNo weight limit

World Thai Boxing Association (Junior Amateur and Adult)

Junior Pin Weight 47 lb (21.36 kg)
Junior Atom Weight 52 lb (23.64 kg)
Junior Straw Weight 57 lb (25.91 kg)
Junior Fly Weight 62 lb (28.18 kg)
Junior Bantam Weight 67 lb (30.45 kg)
Junior Feather Weight 72 lb (32.73 kg)
Junior Light Weight 77 lb (35 kg)
Junior Welter 77 lb (35 kg)
Junior Middle 87 lb (39.55 kg)
Junior Cruiser 92 lb (41.82 kg)
Junior Heavy 97 lb (44.09 kg)
Girls/Boys Pin Weight 102 lb (46.36 kg)
Girls/Boys Atom Weight 107 lb (48.64 kg)
Girls/Boys Straw Weight 112 lb (50.91 kg)
Girls/Boys Fly Weight 117 lb (53.18 kg)
Girls/Boys Bantam Weight 122 lb (55.45 kg)
Girls/Boys Feather Weight 127 lb (57.73 kg)
Girls/Boys Light Weight 132 lb (60 kg)
Girls/Boys Super Light Weight 137 lb (62.27 kg)
Girls/Boys Light Welter 142 lb (64.55 kg)
Girls/Boys Welter Weight 147 lb (66.82 kg)
Girls/Boys Super Welter 153 lb (69.55 kg)
Girls/Boys Light Middle 159 lb (72.27 kg)
Girls/Boys Middle Weight 165 lb (75 kg)
Girls/Boys Super Middle 172 lb (78.18 kg)
Girls/Boys Light Heavy Weight 179 lb (81.36 kg)
Girls/Boys Light Cruiser 186 lb (84.55 kg)
Girls/Boys Cruiser Weight 195 lb (88.64 kg)
Girls/Boys Heavy Weight 215 lb (97.73 kg)
Girls/Boys Super Heavy 215 lb (97.73 kg)
Pin Weight 102 lb (46.36 kg)
Atom Weight 107 lb (48.64 kg)
Straw Weight 112 lb (50.91 kg)
Fly Weight 117 lb (53.18 kg)
Bantam Weight 122 lb (55.45 kg)
Feather Weight 127 lb (57.73 kg)
Light Weight 132 lb (60 kg)
Super Light Weight 137 lb (62.27 kg)
Light Welter Weight 142 lb (64.55 kg)
Welter Weight 147 lb (66.82 kg)
Super Welter Weight 153 lb (69.55 kg)
Light Middle Weight 159 lb (72.27 kg)
Middle Weight 165 lb (75 kg)
Super Middle Weight 172 lb (78.18 kg)
Light Heavy Weight 179 lb (81.36 kg)
Light Cruiser Weight 186 lb (84.55 kg)
Cruiser Weight 195 lb (88.64 kg)
Heavy Weight 215 lb (97.73 kg)
Super Heavy Weight 215 lb (97.73 kg)

ONE Championship

Atomweight114.8 lb (52.2 kg)
Strawweight124.7 lb (56.7 kg)
Flyweight134.6 lb (61.2 kg)
Bantamweight144.8 lb (65.8 kg)
Featherweight154.7 lb (70.3 kg)
Lightweight169.6 lb (77.1 kg)
Welterweight184.5 lb (83.9 kg)
Middleweight204.6 lb (93.0 kg)
Light Heavyweight224.6 lb (102.1 kg)
Heavyweight264.5 lb (120.2 kg)

Why Do Weight Classes Exist?

Weight classes exist to keep fighters safe. Their intent is to have fighters compete against other competitors who are at or near the same average height and body weight.

It makes sense when you think about the physics.

Force = mass * acceleration

It just wouldn’t make sense to have featherweights competing with heavyweights. They’d get destroyed.

Why Do Muay Thai Fighters Cut Weight?

As I wrote above, size does matter. Professionals usually weigh heavier than their fight weight. This is what people mean when they say so-and-so “walks around” at x lbs. A fighter can cut lots of water weight before weighing in and then rehydrate another 10lb+ and have a serious bodyweight advantage come fight time.

In Thailand, the practice of weight cuts is partially limited by same day weigh ins. Skilled champions like Saenchai even give up the weight advantage to make a fight more evenly matched. He has given up to 15lb+ to opponents by moving up weight classes.

Many fighters cut weight mainly because other fighters cut weight too, and you don’t want your opponent having too much of an advantage.

Some promotions like ONE Championship use walking weight to determine weight divisions. Fighters are checked periodically during their fight camps, and daily during fight week. They also check urine samples for hydration. This ensures a safe weight cut and fair competition.

Should Amateurs Cut Weight for a Fight?

In my personal opinion, if you’re just starting out and not getting paid to fight then it’s not worth it to cut weight. Cutting weight is hard, grueling work.

If you’re in an elite class for a tournament, or are thinking about going pro one day then yeah consider making the cut. Just know that it’s going to suck.

How to Cut for a Fight

Cutting weight is serious business and takes weeks to months of preparation. Typically the amount of water you can safely cut depends on the time between weigh ins and the actual bout.

Weigh-ins are usually the day before or the morning of the fight. This only gives you 12-24 hours to hydrate up.

Professionals have teams who help get them fight-ready. This team usually includes a strength coach and a dietician/nutrition expert in addition to their trainers. As an amateur, it might be hard to hire a professional nutritionist, so you’ll have to manage your caloric intake and macronutrients by yourself on top of everything else.

Traditional methods of water cutting include sodium manipulation, sweating it out in the sauna or with a sauna suit, taking hot baths in epsom salts, wearing sweats to bed, and chewing gum and spitting. It’s a miserable experience.

After putting in all that work, what happens if you miss weight? You might get additional time to shave off a half-pound. Sometimes the promoter will still let the fight go ahead, but you lose a percentage of your purse. Other organizations won’t let you fight at all.