The Sun Bear stands approximately 1.2 m (4 ft) in length, making it the smallest member in the bear (Ursidae) family. Males tend to be 10-45% larger than females;the former normally weigh between 30 and 60 kg (66-132 lb), the latter between 20 and 40 kg (44-88 lb).The Sun Bear possesses sickle-shaped claws that are relatively light in weight. It has large paws with naked soles, probably to assist in climbing. Its inward-turned feet make the bear's walk pigeon-toed, but it is an excellent climber. It has small, round ears and a stout snout. The tail is 1.2-2.8 inches (3-7 cm) long. Despite its small size, the Sun Bear possesses a very long, slender tongue, ranging from 8 to 10 inches (20-25 cm) in length. The bear uses it to extract honey from beehives.
Unlike other bears, the Sun Bear's fur is short and sleek. This adaptation is probably due to the lowland climates it inhabits. Dark black or brown-black fur covers its body, except on the chest, where there is a pale orange-yellow marking in the shape of a horseshoe. Similar colored fur can be found around the muzzle and the eyes. These distinctive markings give the Sun Bear its name.