In the UFC, the lightweight division is for athletes who weigh up to 156 pounds for non-title bouts, while title fights require athletes to weigh in at or under 155 pounds. The UFCs lightweight division groups competitors within 146 to 155 lb (66 to 70 kg) ). The Association of Boxing Commissions defines the lightweight weight class as over 145 to 155 lbs, with a 5 lbs allowance.

In mixed martial arts, the lightweight division contains different weight classes depending on the organization. For example, the Shooto lightweight division limits competitors to 145 lb (65.8 kg), while the ONE Championships lightweight division has an upper limit at 77.1 kg (170.0 lb) ). However, for the sake of uniformity, most American mixed martial arts media outlets consider lightweight competitors to be between 146 and 155 lb (66 and 70 kg) ).