How much a kitten weighs at birth, how fast it grows and when it becomes an adult
For comparison, ordinary domestic kittens weigh 70–120 g at birth.
Only by this age are the muscles and skeleton fully formed.
The biggest kittens of any cat breed. The difference from ordinary domestic cats is genetic.
The fastest weight gain. After 8–10 months the pace starts to slow.
Already looks big, but this isn't its final shape: it's still growing.
A broad chest, heavy bone and solid muscle: the body is fully developed.
| Age / stage | Males | Females | Notes |
|---|---|---|---|
| At birth | 120–170 g | 120–170 g | Bigger than kittens of other breeds |
| 3 months | 1.5–2.5 kg | 1.2–2.0 kg | Age kittens go to new homes |
| 6 months | 4–5 kg | 3–4 kg | Rapid weight gain |
| 1 year | 7–8 kg | 4.5–6.5 kg | Big, but not yet adult |
| 3–4 years | 10–11 kg | 7–8 kg | Fully developed |
Males are bigger than females, and that's normal. If your girl weighs 6–7 kg, that's an excellent weight for the breed.
Even within one litter, one kitten may grow to 9 kg and another to 12 kg. A lot depends on the parents' weight and build.
What matters is growing in proportion. A sharp shortfall in weight, or obesity, is a reason to consult a vet and the breeder.
The 15+ kg cats on social media are the exception. A healthy Maine Coon is a big, active, well-built cat.
How a Maine Coon grows: from 120 grams at birth to 10+ kg by 3–4 years
Maine Coons are called "gentle giants" for a reason. Their growth and weight gain is a long, uneven process, and it's worth understanding it so that you don't worry about your cat's health or expect an "adult" shape too early.
Here are the stages of a Maine Coon's growth, in figures.
From the moment it's born, a Maine Coon kitten already stands out from other breeds by its weight.
Average birth weight of Maine Coon kittens: 120–170 grams
For comparison, an ordinary domestic cat's kittens weigh 70–120 grams at birth. That's a noticeable difference, and it's genetic: this is one of the largest cat breeds in the world.
Maine Coons put on weight fastest up to 10–12 months.
After 8–10 months growth starts to slow, but the kitten keeps gaining weight.
Average weight at 1 year:
| Sex | Weight |
|---|---|
| Males | 7–8 kg |
| Females | 4.5–6.5 kg |
Bear in mind that at one year a Maine Coon already looks big, but this isn't its final shape yet.
Maine Coons finish growing and developing physically only by 3–4 years.
By this age the cat has fully developed:
Average adult Maine Coon weight at 3–4 years:
| Sex | Weight |
|---|---|
| Males | 10–11 kg |
| Large females | 7–8 kg |
1. Males and females differ a lot. Males are bigger than females, and that's normal. If your girl weighs 6–7 kg, that's an excellent weight for the breed.
2. Genetics decides. Even in one litter there may be kittens that grow to 9 kg and others that reach 12 kg. A lot depends on the parents: their weight, build and ancestry.
3. Weight isn't the goal. What matters isn't "piling on the kilos" but growing in proportion. A sharp shortfall or, at the other extreme, obesity is a reason to consult a vet and the breeder.
4. Don't compare your cat with internet "record-breakers". Social media is full of cats weighing 15+ kg. They're the exception rather than the rule. A healthy Maine Coon is a big but active, well-built cat.
| Stage | Notes |
|---|---|
| Birth | 120–170 g |
| Up to 10–12 months | Active growth |
| 1 year | Males 7–8 kg, females 4.5–6.5 kg |
| 3–4 years | Fully developed, males up to 10–11 kg |
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