Cat Care
When Do Cats Stop Growing? Age Chart for Kittens to Adults
Most cats stop growing between 12 and 18 months of age. Female cats often reach adult size around 10 to 12 months, while males may keep filling out until about 18 months. Large, slow-maturing breeds such as the Maine Coon and Norwegian Forest Cat can keep growing until around 2 years or later.
Cat growth by age
| Age | What's happening |
|---|---|
| 0–8 weeks | Fastest growth. Eyes open, teeth come in, weaning starts. See our week-by-week kitten age chart. |
| 2–6 months | Rapid growth continues. Adult teeth replace baby teeth from about 3–4 months. Growth plates can start to close around 4–5 months. |
| 6–12 months | Growth slows. Many cats look adult-sized; females often finish around 10–12 months. |
| 12–18 months | Most cats reach full adult size and weight. Males may still be filling out. |
| 18 months–2+ years | Large breeds like Maine Coons and Norwegian Forest Cats may still be growing. |
Timings follow PetMD, which notes the typical cat reaches adult size by 12 to 18 months. Every cat is different, so treat these as ranges.
Do male cats grow longer than females?
Often, yes. Females tend to finish growing earlier, around 10 to 12 months, and males may keep growing until about 18 months and end up larger.
Breed differences
- Large, slow-maturing breeds such as Maine Coon and Norwegian Forest Cat: may grow until about 2 years or later.
- Most domestic shorthairs and mixed-breed cats: usually adult size by 12 to 18 months.
- Small breeds such as the Singapura: may finish growing by around 9 months.
Does neutering affect growth?
Spaying or neutering can delay when the growth plates close, so neutered cats may grow for a little longer. It doesn't stunt growth. Neutered cats do often need fewer calories, so keep an eye on weight after surgery.
How to tell if your cat is still growing
- Weigh your cat every few weeks; steady gains in a young cat usually mean growth.
- Look for longer legs and body length, not just a bigger belly.
- Big paws and gangly proportions are typical of a growing cat.
- If you need to know for sure, your vet can check, and X-rays show whether growth plates have closed.
Weight gain after growth has stopped is usually fat, not growth. Ask your vet if your adult cat keeps getting heavier.
When to switch from kitten food to adult food
Kitten food has more calories, protein and fat for growth. Many cats switch around 12 months, and large breeds may stay on it longer. There is no single right age, so ask your vet, and change foods gradually over about a week.
Frequently asked questions
At what age is a cat fully grown?
Most cats are fully grown between 12 and 18 months. Large breeds such as Maine Coons can keep growing until about 2 years or later.
Is a 1 year old cat still a kitten?
At 1 year, most cats are considered adults, though many are still filling out and may grow a little more until 18 months.
When do male cats stop growing?
Male cats often keep growing until around 18 months, a little longer than females.
When do female cats stop growing?
Female cats often reach adult size around 10 to 12 months.
Do indoor cats grow bigger?
Living indoors doesn't change how big a cat grows. Genetics, breed, sex and nutrition matter most, though indoor cats can gain extra weight if they eat more than they burn.
Sources
Guidance follows PetMD. This article is general information, not veterinary advice.
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