When do kittens stop growing

See the kitten growth chart from Pet Health Club and learn when kittens are finished growing.

Photo of an adult cat with two kittens, attached to an article

Overview

Most kittens reach full size between 12 and 18 months, but their growth can reveal early signs of health issues too. Research shows that kittens who gain weight too fast are more likely to become overweight adults, while regular weighing can help spot potential illnesses early. Kitten growth doesn’t happen all at once, and it varies between breeds.

From birth to eight weeks: Newborn phase

Two to six months: playful, growing fast

Six to 12 months: looking grown-up

Beyond 12 months: when growth stops

Kitten growth timeline at a glance

What science says about helping your kitten grow

Salt, C., German, A.J., Henzel, K.S. and Butterwick, R.F., 2022. Growth standard charts for monitoring bodyweight in intact domestic shorthair kittens from the USA. PLOS ONE, 17(11), p.e0277531. https://doi.org/10.1371/journal.pone.0277531

Berliner, E.A., Scarlett, J.M., Cowan, A.C. and Mohammed, H., 2022. A prospective study of growth rate, disease incidence, and mortality in kittens less than 9 weeks of age in shelter and foster care. Journal of Applied Animal Welfare Science, 25(6), pp.607–622. https://doi.org/10.1080/10888705.2021.2021409

Opsomer, H., Liesegang, A., Brugger, D. and Wichert, B., 2022. Growth curves and body condition of young cats and their relation to maternal body condition. Animals, 12(11), p.1453. https://doi.org/10.3390/ani12111453

American Veterinary Medical Association (AVMA), 2021. Pet Ownership and Demographics Sourcebook. Schaumburg: AVMA.

Cornell University College of Veterinary Medicine, 2020. Feline Development and Socialization. Ithaca: Cornell Feline Health Center. Available at: https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center

Hill’s Pet Nutrition, 2023. Kitten Developmental Milestones. Available at: https://www.hillspet.com/cat-care/kitten-care/kitten-growth-milestones

Rezende, M.P.F., et al., 2020. Radiographic growth plate closure times in domestic cats. Journal of Feline Medicine and Surgery, 22(2), pp.197–203. doi:10.1177/1098612X19877836.

Royal Canin Vet Focus, 2021. Understanding the Stages of Kitten Development. Vet Focus. Available at: https://vetfocus.royalcanin.com/en/kitten-development-stages

Medically reviewed by Lizzie Youens, BSc(Hons) BVSc MRCVS

Published on 15/05/2025 • Reviewed on 15/05/2025