Muay Thai Weight Classes

What’s the purpose of weight classes in Muay Thai?

To make Muay Thai matches fairer, fighters are marched together by weight.  This helps ensure that fighters are going to be roughly the same size.  

This seems quite obvious but, everything else being equal, larger fighters are going to be able to hit harder than lighter fighters.  They simply have more mass.  Even if their punches travel at the same speed, they will deliver more force.  

Fights between fighters of unequal weight would therefore be unbalanced.  Larger fighters would be able to inflict more damage than the smaller fighter making it more likely that they would be able to land a knock out punch to win the fight.

I’ve written on a similar topic here – Does height matter in a fight?

Such one sided fights wouldn’t be particularly entertaining to watch as, generally speaking, it more interesting to see which is the more skillful fighter.

Fighters therefore compete against other fighters in the same weight category.

Weight divisions in Muay Thai Associations

Different Muay Thai Associations have different weight divisions.

United States Muaythai Federation (USMF)

Adult – Youth Male and Female

Pin Weight – 102 lbs and Under

Atom Weight- 102.1- 107 lbs

StrawWeight-  107.1- 112 lbs

Fly Weight – 112.1- 117 lbs

BantamWeight- 117.1- 122 lbs

Featherweight-  122.1- 127 lbs

Lightweight- 127.1 – 132 lbs

Super Lightweight- 132.1 – 137 lbs

Light Welter- 137.1 – 142 lbs

Welterweight- 142.1- 147 lbs

Super Welter- 147.1- 153 lbs

Light Middle- 153.1 – 159 lbs

Middleweight- 159.1- 165 lbs

Super Middle- 165.1- 172 lbs

Light HeavyWeight- 172.1- 179 lbs

Light Cruiser- 179.1- 186 lbs

Cruiser Weight- 186.1- 195 lbs

Heavy Weight- 195.1- 215 lbs

Super Heavy- 215.1 and Above lbs

Youth Male and Female Ages (10-17)

Youth PinWeight- 47 lbs and Under

Youth AtomWeight- 47.1- 52 lbs

Youth StrawWeight- 52.1- 57 lbs

Youth Flyweight- 57.1- 62 lbs

Youth Bantamweight- 62.1- 67 lbs

Youth Featherweight- 67.1-  72 lbs

Youth Lightweight- 72.1- 77 lbs

Youth Welter- 77.1 – 82 lbs

Youth Middle- 82.1- 87 lbs

Youth Cruiser- 87.1- 92 lbs

Youth Heavy- 92.1- 97 lbs


Kru Muaythai Association

Mini Flyweight – 105 lbs

Light Flyweight – 108 lbs 

Flyweight – 112 lbs

Super Flyweight – 115 lbs

Bantamweight – 118 lbs

Super Bantamweight – 122 lbs

Featherweight – 126 lbs

Super Featherweight – 130 lbs

Lightweight – 135 lbs

Super Lightweight – 140 lbs

Welterweight – 147 lbs

Super Welterweight – 154 lbs

Middleweight – 160 lbs

Super Middleweight – 168 lbs

Light Heavyweight – 175 lbs

Cruiserweight – 200 lbs

Heavyweight – 265 lbs


World Muaythai Council

Mini Fly Weight – 105 lbs

Light-Fly Weight – 108 lbs

Fly Weight – 112 lbs

Super Fly Weight – 115 lbs

Bantam Weight – 118 lbs

Super Bantam Weight – 122 lbs

Feather Weight – 126 lbs

Super Feather  Weight – 130 lbs

Light Weight – 135 lbs 

Super Light Weight – 140 lbs

Welter Weight – 147 lbs

Super Welter Weight – 154 lbs

Middle Weight – 160 lbs

Super Middle Weight – 168 lbs

Light Heavy Weight – 175 lbs

Super Light Heavy Weight – 182 lbs

Cruiser Weight – 190 lbs

Heavy Weight – 209 lbs

Super Heavy Weight – 209+ lbs



When do boxers weigh-in before a fight?

The timing of the weigh-in varies between different Associations.

The World Muaythai Council dictates that the fighters must weigh-in no more than 24 hours before the actual fight.  The weigh-in itself is done without clothes and just before, the fighters have a physical examination by a doctor to ensure they are physically fit enough to fight.

Contestants in United States Muaythai Federation are required to weigh-in on the morning of the competition or the day before the first competition day.  There is a three hour window following the close of the weigh-in and the fight, although this time can be shortened by the officials.  Male and female fighters complete the weigh-in wearing light underwear.

The Kru Muaythai Association specifies that fighters must weigh-in at least 3 hours before the fight.  They are not permitted to wear clothes whilst they complete the weigh-in.

Related Reading

Muay Lao vs Muay Thai: is there a difference?

Bang Muay Thai: a new martial art style!

Can Muay Thai be used in a street fight?

Can you use elbows in Muay Thai?

What moves are illegal in Muay Thai?

23 Muay Thai techniques -beginner and advanced [with GIFS!]