Gi is a short form of keikogi, meaning practice clothes, and it refers to the traditional uniform worn for training in judo, karate, jujitsu and several related martial arts. A typical gi consists of a jacket that wraps left over right and is held shut by an obi, or belt, along with loose fitting trousers. The exact cut, weight and fit vary by style, which is why judogi, karategi and BJJ gi are treated as distinct types of gi.
For training, a gi needs to survive being gripped, pulled and thrown around, so fabric weight and weave matter more than they might for ordinary sportswear. Weight is usually stated in grams per square metre or ounces, and heavier, denser weaves generally hold up better to grappling than light, single weave fabric suited to striking arts. Correct fit also matters: a gi that is too large catches on grips and looks untidy, while one that is too small restricts movement.
Our gi sizing and shrinkage guide explains how to pick a size that survives washing, and gi care and washing covers keeping a uniform in good condition. See also the entry on gi weight for how the different units compare.
