Guide · Growth
Kitten weight by week: what the growth data shows
Typical kitten weights by week for females and males from U.S. vet data, how fast kittens gain, when they finish growing and when to call your vet.
Growth
Kitten weight chart, week by week
Where a kitten’s weight sits on centile lines from open data, 8 to 78 weeks, in grams or pounds.
Kitten weight chart
Examplefemale, 16 weeks, 1,500 g
Where she sits · 16 weeks
about the16thcentile
At 16 weeks, 1,500 g is between the 9th and 25th centile lines for female kittens (1.41–1.60 kg at this age).
- Adult estimate
- 3.51 kghalf end 3.08–3.95 kg
- Grown now
- 43%of adult weight
- Growth ends
- 7–12 monthssources differ
8 in 10 end at 2.72–4.30 kg. From a research colony of intact domestic shorthair cats (242–342 cats per age) — wide for other breeds.
Sources checked How the math works Data and sources
- today’s weight
- centile lines, 2nd to 98th (dashed where estimated between measured ages)
The lines were built from domestic shorthair kittens; pedigree breeds such as the Maine Coon or Persian may sit higher or lower.
Kitten bands derived by Puppy Scale from Salt et al. (2022), data: University of Liverpool DataCat 1456, licensed CC BY 3.0. Our tables are empirical summaries, not the published model curves.
Talk to your vet. This is an estimate, not veterinary advice. Puppy Scale is not a veterinary practice and can’t examine your pet.
Estimate by Puppy Scale · sources checked October 7, 2026 · not veterinary advice · puppyscale.com
How the math works
Each rule below with its data and the date we read it. The example is a female kitten of 16 weeks weighing 1,500 g.
- The centile lines
For each sex, the 2nd, 9th, 25th, 50th, 75th, 91st and 98th centile of kittens’ weights in four-week windows, shown from 8 to 78 weeks; straight lines between weeks. Where the study had too few visits at an age, the lines are drawn dashed: estimated between measured ages.
Example: 1,500 g at 16 weeks is between the 9th and 25th centile lines, about the 16th centile.
Growth standard charts for monitoring bodyweight in intact domestic shorthair kittens from the USA, read · Growth standard charts for monitoring bodyweight in Domestic Shorthair kittens - SUPPORTING DATA, read
- Adult estimate
Today’s weight ÷ the median share of adult weight at this age, from cats in a research colony (adult = weight at 1.5 years or older), 8 to 65 weeks; the middle half and 8 in 10 from the 25th–75th and 10th–90th percentiles, never below today’s weight. Example: about 3.51 kg, half end at 3.08–3.95 kg.
All domestic shorthair cats in one colony — wide for other breeds and for pet cats.
Growth standard charts for monitoring bodyweight in intact domestic shorthair kittens from the USA, read · Growth standard charts for monitoring bodyweight in Domestic Shorthair kittens - SUPPORTING DATA, read
- Weekly gain (young kittens)
The difference between two weigh-ins divided by the weeks between them, compared with the 50–100 g a week a veterinary reference gives for the first 3–4 months.
- When growth ends
Most kittens finish growing at about 7–12 months; sources differ, so we give the range, not one age.
Feeding Practices in Small Animals, read · Growth standard charts for monitoring bodyweight in intact domestic shorthair kittens from the USA, read
What this doesn’t cover
Breed charts: Not modeled — no open growth data exist for pedigree breeds; the lines come from domestic shorthair kittens (checked October 7, 2026).
Neutering: Not modeled — the colony cats were intact and the effect of neutering on the curve is not modeled (checked October 7, 2026).
Centiles under 8 weeks: Not modeled — the published standards start at 8 weeks — use the weekly-gain check (checked October 7, 2026).
Adult weight after 65 weeks: Not modeled — the colony table ends at 65 weeks; by then most cats are close to adult weight (checked October 7, 2026).
Data licences
Kitten bands derived by Puppy Scale from Salt et al. (2022), data: University of Liverpool DataCat 1456, licensed CC BY 3.0. Our tables are empirical summaries, not the published model curves.