How Big Do Maine Coons Get? Size, Weight & Growth Timeline

Average adult weight and length by gender, how long it takes a Maine Coon to reach full size, and what actually affects how big yours will grow.

Maine Coons are famous for their size, but exactly how big is "big," and how long does it take to get there?

1. Average Weight and Length by Gender

Adult males typically weigh 8–13kg with a body length (nose to tail) up to 120cm. Adult females are noticeably smaller, averaging 5.5–8kg. Some exceptionally large males exceed these ranges, but anything advertised as guaranteed "20kg+" should be treated with scepticism — that's well outside normal, healthy range for the breed.

2. The 3–5 Year Growth Timeline

Unlike most cat breeds that reach full adult size by 12 months, Maine Coons keep growing — in stages — for 3 to 5 years. Kittens often go through visibly gawky, long-legged phases before their body proportions catch up, similar to large dog breeds.

3. What Affects Final Size

Genetics from both parents set the ceiling, but nutrition during the growth years matters enormously — a diet with adequate protein and the right calcium-to-phosphorus ratio supports healthy skeletal development, while poor nutrition during those years can permanently limit growth. Neutering timing can also have a modest effect on final frame size.

4. Space Considerations for a Growing Giant

A full-size Maine Coon needs sturdier furniture than a standard cat — a flimsy scratching post will topple under an adult male's weight and leaping force. Factor this into your setup well before they reach full size.

FAQ

How heavy do Maine Coons get? 8–13kg for males, 5.5–8kg for females, on average.

How long until a Maine Coon is fully grown? 3–5 years, much longer than most cat breeds.

Are Maine Coons the biggest cat breed? They're widely regarded as the largest commonly-kept domestic cat breed by average size.

See our current available kittens from proven large-bodied lines: Shop.