In order for bodybuilders to compete against men of similar size, the IFBB has instituted weight classes for all amateur competition:
a. Bantamweight: Up to and incl 65 Kg.
b. Lightweight: Up to and incl 70 Kg.
c. Welterweight: Up to and incl 75 Kg.
d. Light-Middleweight: Up to and incl 80 Kg.
e. Middleweight Up to and incl 85 Kg.
f. Light-heavyweight: Up to and incl 90 Kg.
g. Heavyweight: Over 90 Kg.

Women's Professional Bodybuilding, all competitions shall have two (2) weight categories as follows:
a. Lightweight: up to & including 135 lbs [61.364 kg]
b. Heavyweight: Over 135 lbs [61.364 kg]