Males are usually 71 to 76 centimetres (28 to 30 in) tall at the withers, and weigh on average 27 to 40 kilograms (60 to 88 lb). Females tend to be smaller, with shoulder heights ranging from 66 to 71 centimetres (26 to 28 in) and weights from 25 to 34 kilograms (55 to 75 lb), although weights can be above and below these average weights. Greyhounds have very short fur, which is easy to maintain. There are approximately thirty recognized color forms, of which variations of white, brindle, fawn, black, red and blue (gray) can appear uniquely or in combination. Greyhounds are dolichocephalic, with a skull which is relatively long in comparison to its breadth, and an elongated muzzle.