How Big Is the Average Backyard Rabbit? How Much Does a Cottontail Rabbit Weigh? How Big Is a Chinchilla? What is the Average Size of a New Zealand White Rabbit? How Big is a Champagne Rabbit? If you’re considering bringing a cottontail rabbit into your backyard, it’s important to know how big it can get. The eastern cottontail rabbit measures 36 to 48 cm, which is about 14 to 19 inches in length. Its tail is small. The female cottontail is larger than the male, but both weigh about the same. The weight of a cottontail is approximately one and a half pounds. The ears of this small animal are about 60 mm long. They’re a good size for a backyard pet, but they’re easy prey for other animals like coyotes, foxes, and bobcats. The winter months are the most dangerous for rabbits. Snow covers the ground and makes them vulnerable to predation. The cottontail doesn’t turn white during this time, unlike its larger cousin, the snowshoe hare. However, when snow covers the ground, the rabbits have to forage far and are vulnerable to predators.