Normal Size & Weight of an Adult Ferret

With a life span of up to 10 years, ferrets reach their adult weight, and are considered fully grown, at just 4 months old. While generally healthy eaters, underlying medical conditions can cause ferrets to be either underweight or overweight. Knowing a ferret’s average height and weight can help you determine if you should discuss your ferret’s weight and size with your veterinarian.

White domestic ferret taking a walk.
A Silver Mitt Ferret on a leash
credit: TomLester/iStock/Getty Images

Average Height and Weight

A full grown, adult ferret can weigh between 1 and 4 pounds and measure between 18 to 24 inches long, depending on the gender. Females tend to be smaller, weighing between 1 and 2.5 pounds and measuring approximately 18 inches long from the nose to the tip of the tail. Male ferrets are the larger sex of the species, ranging between 2 and 4 pounds. The average male ferret is also longer, averaging about 24 inches from the nose to tail tip.