factor. There are nine different weight classes in the Unified Rules of Mixed Martial Arts . These nine weight classes include flyweight (up to 125 lb / 56.7 kg), bantamweight (up to 135 lb / 61.2 kg), featherweight (up to 145 lb / 65.8 kg), lightweight (up to 155 lb / 70.3 kg), welterweight (up to 170 lb / 77.1 kg), middleweight (up to 185 lb / 83.9 kg), light