The Sugar Glider is around 15 to 20 cm (6.3 to 7.5 inches) in length, with a tail longer than the body and almost as thick as a human thumb, and weighs between 90 and 150 grams (3 to 5.3 oz). The fur is generally pearl grey, with black and cream patches on the underbelly and black or grey ears. Other colour variations include leucistic and albino recessive traits. The tail tapers only moderately and the last quarter of it is black, often with a dark tip. The muzzle is short and rounded. Northern forms tend to be brown coloured rather than grey and smaller.
The most distinctive features of its anatomy are the twin skin membranes called patagia which extend from the fifth finger of the forelimb back to the first toe of the hind foot. flabby – but immediately obvious when it takes flight. The membranes are used to glide between trees: when fully extended they form an aerodynamic surface the size of a large handkerchief. Membranes are also used to gather food while hunting. The membrane has a thin sheet of fur surrounding it, but it is usually pink in colour.
The gliding membranes are primarily used as an efficient way to get to food resources. They may also, as a secondary function, help the Sugar Glider escape predators like goannas, introduced foxes and cats, and the marsupial carnivores, such as quolls, the Kowari, mulgaras, and antechinuses that foxes, cats, and dingos largely supplanted. The ability to glide from tree to tree is clearly of little value with regard to the Sugar Glider's avian predators, however, in particular owls and kookaburras. The sugar gliders membrane allows it to glide for considerable distance. When landing, they catch on to branches with their sharp feet and opposable thumbs.
Although its aerial adaptation looks rather clumsy in comparison to the highly specialised limbs of birds and bats, the Sugar Glider can glide for a surprisingly long distance — flights have been measured at over 50 metres (55 yd) — and steer effectively by curving one patagium or the other. It uses its hind legs to thrust powerfully away from a tree, and when about 3 metres (3 yd) from the destination tree trunk, brings its hind legs up close to the body and swoops upwards to make contact with all four limbs together.