Kitten weight chart by week and month
How much should your kitten weigh? This chart shows the typical weight of healthy male and female domestic shorthair kittens from 8 weeks to 18 months: the median and the range where most kittens sit, week by week and month by month, from our fit of the open Waltham data.
Updated
Kitten growth chart
The line is the median; the bands hold the middle half and the middle 82% of healthy kittens at each age. Males and females have separate panels.
- Median
- Middle half (25th–75th centile)
- Typical range (9th–91st centile)
Our fit of the open Waltham data, not the official WALTHAM chart. See the official WALTHAM kitten growth charts (opens in a new tab).
Kitten weight by week and month
Weekly from 8 to 16 weeks, then monthly to 18 months. Pounds with kilograms below.
| Age | 9th | 25th | Median | 75th | 91st |
|---|---|---|---|---|---|
| 8 weeks | 1.30.57 | 1.50.70 | 1.90.86 | 2.31.06 | 2.81.28 |
| 9 weeks | 1.50.68 | 1.80.83 | 2.21.01 | 2.71.21 | 3.21.45 |
| 10 weeks | 1.80.80 | 2.10.97 | 2.61.16 | 3.01.38 | 3.61.63 |
| 11 weeks | 2.00.93 | 2.41.11 | 2.91.32 | 3.41.56 | 4.01.82 |
| 12 weeks | 2.31.06 | 2.81.26 | 3.31.48 | 3.81.74 | 4.42.01 |
| 13 weeks | 2.61.19 | 3.11.41 | 3.61.65 | 4.21.91 | 4.92.20 |
| 14 weeks | 2.91.32 | 3.41.55 | 4.01.81 | 4.62.09 | 5.32.39 |
| 15 weeks | 3.21.45 | 3.71.70 | 4.31.97 | 5.02.26 | 5.72.57 |
| 16 weeks | 3.51.57 | 4.01.84 | 4.72.12 | 5.32.42 | 6.02.74 |
| 4 months (17 wk) | 3.71.69 | 4.31.97 | 5.02.27 | 5.72.58 | 6.42.91 |
| 5 months (22 wk) | 4.92.22 | 5.62.56 | 6.42.92 | 7.23.28 | 8.13.66 |
| 6 months (26 wk) | 5.62.55 | 6.52.93 | 7.33.32 | 8.23.72 | 9.14.13 |
| 7 months (30 wk) | 6.22.80 | 7.13.21 | 8.03.63 | 8.94.06 | 9.94.49 |
| 8 months (35 wk) | 6.73.02 | 7.63.46 | 8.63.91 | 9.64.37 | 10.74.83 |
| 9 months (39 wk) | 6.93.14 | 7.93.60 | 9.04.07 | 10.04.55 | 11.15.03 |
| 10 months (43 wk) | 7.13.24 | 8.23.71 | 9.34.20 | 10.34.69 | 11.45.19 |
| 11 months (48 wk) | 7.33.32 | 8.43.81 | 9.54.31 | 10.64.83 | 11.85.34 |
| 12 months (52 wk) | 7.43.36 | 8.53.87 | 9.74.38 | 10.84.91 | 12.05.44 |
| 15 months (65 wk) | 7.63.46 | 8.83.98 | 10.04.53 | 11.25.08 | 12.45.64 |
| 18 months (78 wk) | 7.73.51 | 8.94.05 | 10.24.62 | 11.45.19 | 12.75.76 |
| Age | 9th | 25th | Median | 75th | 91st |
|---|---|---|---|---|---|
| 8 weeks | 1.40.65 | 1.60.75 | 1.90.88 | 2.31.03 | 2.71.23 |
| 9 weeks | 1.60.74 | 1.90.86 | 2.21.00 | 2.61.17 | 3.01.36 |
| 10 weeks | 1.90.84 | 2.10.97 | 2.51.12 | 2.91.30 | 3.31.50 |
| 11 weeks | 2.10.94 | 2.41.08 | 2.71.24 | 3.11.43 | 3.61.63 |
| 12 weeks | 2.31.04 | 2.61.19 | 3.01.37 | 3.41.56 | 3.91.76 |
| 13 weeks | 2.51.13 | 2.91.30 | 3.31.49 | 3.71.69 | 4.21.90 |
| 14 weeks | 2.71.23 | 3.11.41 | 3.51.61 | 4.01.81 | 4.52.03 |
| 15 weeks | 2.91.33 | 3.31.52 | 3.81.72 | 4.31.94 | 4.82.16 |
| 16 weeks | 3.11.42 | 3.61.62 | 4.01.83 | 4.52.05 | 5.02.28 |
| 4 months (17 wk) | 3.31.51 | 3.81.72 | 4.31.94 | 4.82.17 | 5.32.40 |
| 5 months (22 wk) | 4.11.86 | 4.72.11 | 5.22.37 | 5.82.63 | 6.42.89 |
| 6 months (26 wk) | 4.52.06 | 5.12.33 | 5.72.60 | 6.42.89 | 7.03.17 |
| 7 months (30 wk) | 4.82.19 | 5.42.47 | 6.12.77 | 6.83.07 | 7.53.38 |
| 8 months (35 wk) | 5.12.29 | 5.72.59 | 6.42.90 | 7.13.23 | 7.93.58 |
| 9 months (39 wk) | 5.22.35 | 5.82.65 | 6.62.98 | 7.33.33 | 8.23.70 |
| 10 months (43 wk) | 5.32.39 | 5.92.70 | 6.73.04 | 7.53.41 | 8.43.81 |
| 11 months (48 wk) | 5.42.43 | 6.02.74 | 6.83.09 | 7.73.49 | 8.73.93 |
| 12 months (52 wk) | 5.42.45 | 6.12.77 | 6.93.13 | 7.83.55 | 8.94.03 |
| 15 months (65 wk) | 5.52.51 | 6.32.84 | 7.13.24 | 8.23.73 | 9.54.33 |
| 18 months (78 wk) | 5.62.56 | 6.42.90 | 7.33.33 | 8.63.90 | 10.24.64 |
How much should my kitten weigh?
The typical weight at each month, with the middle 82% of healthy kittens of the data.
At 2 months
At 2 months (9 weeks), the typical range for male kittens is 1.5–3.2 lb (0.68–1.45 kg), with a median of 2.2 lb (1.01 kg); for females it is 1.6–3.0 lb (0.74–1.36 kg), with a median of 2.2 lb (1.00 kg).
At 3 months
At 3 months (13 weeks), the typical range for male kittens is 2.6–4.9 lb (1.19–2.20 kg), with a median of 3.6 lb (1.65 kg); for females it is 2.5–4.2 lb (1.13–1.90 kg), with a median of 3.3 lb (1.49 kg).
At 4 months
At 4 months (17 weeks), the typical range for male kittens is 3.7–6.4 lb (1.69–2.91 kg), with a median of 5.0 lb (2.27 kg); for females it is 3.3–5.3 lb (1.51–2.40 kg), with a median of 4.3 lb (1.94 kg).
At 5 months
At 5 months (22 weeks), the typical range for male kittens is 4.9–8.1 lb (2.22–3.66 kg), with a median of 6.4 lb (2.92 kg); for females it is 4.1–6.4 lb (1.86–2.89 kg), with a median of 5.2 lb (2.37 kg).
At 6 months
At 6 months (26 weeks), the typical range for male kittens is 5.6–9.1 lb (2.55–4.13 kg), with a median of 7.3 lb (3.32 kg); for females it is 4.5–7.0 lb (2.06–3.17 kg), with a median of 5.7 lb (2.60 kg).
At 7 months
At 7 months (30 weeks), the typical range for male kittens is 6.2–9.9 lb (2.80–4.49 kg), with a median of 8.0 lb (3.63 kg); for females it is 4.8–7.5 lb (2.19–3.38 kg), with a median of 6.1 lb (2.77 kg).
At 8 months
At 8 months (35 weeks), the typical range for male kittens is 6.7–10.7 lb (3.02–4.83 kg), with a median of 8.6 lb (3.91 kg); for females it is 5.1–7.9 lb (2.29–3.58 kg), with a median of 6.4 lb (2.90 kg).
At 9 months
At 9 months (39 weeks), the typical range for male kittens is 6.9–11.1 lb (3.14–5.03 kg), with a median of 9.0 lb (4.07 kg); for females it is 5.2–8.2 lb (2.35–3.70 kg), with a median of 6.6 lb (2.98 kg).
At 10 months
At 10 months (43 weeks), the typical range for male kittens is 7.1–11.4 lb (3.24–5.19 kg), with a median of 9.3 lb (4.20 kg); for females it is 5.3–8.4 lb (2.39–3.81 kg), with a median of 6.7 lb (3.04 kg).
At 11 months
At 11 months (48 weeks), the typical range for male kittens is 7.3–11.8 lb (3.32–5.34 kg), with a median of 9.5 lb (4.31 kg); for females it is 5.4–8.7 lb (2.43–3.93 kg), with a median of 6.8 lb (3.09 kg).
At 12 months
At 12 months (52 weeks), the typical range for male kittens is 7.4–12.0 lb (3.36–5.44 kg), with a median of 9.7 lb (4.38 kg); for females it is 5.4–8.9 lb (2.45–4.03 kg), with a median of 6.9 lb (3.13 kg).
At 18 months
At 18 months (78 weeks), the typical range for male kittens is 7.7–12.7 lb (3.51–5.76 kg), with a median of 10.2 lb (4.62 kg); for females it is 5.6–10.2 lb (2.56–4.64 kg), with a median of 7.3 lb (3.33 kg).
Is my kitten’s weight on track?
Enter your kitten’s sex, age in weeks and weight to see which band of the chart the weight falls in.
Result
Female, 17 weeks, 4.5 lb
Middle half, above the median
Between the median and the 75th centile.
- Typical range at this age
- 3.3–5.3 lb (1.51–2.40 kg)Median 4.3 lb (1.94 kg)
A weight outside the typical range is not a diagnosis. Weigh again on the same scale in a few days, and if it stays there or you are unsure, show the weights to your vet. Body condition matters as much as the number: WSAVA body condition chart for cats (opens in a new tab).
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When do kittens stop growing?
Kittens gain fastest in their first six months. Measured against the weight at 18 months, the median male reaches three quarters of it at about 6 months and 90% at about 10 months; the median female at 6 months and 9 months.
WALTHAM notes that most kittens reach their adult weight by about a year and finish growing by 18 months. Males end up heavier: at 18 months the median male weighs 10.2 lb (4.62 kg) and the median female 7.3 lb (3.33 kg).
For females after about one year, our median is a little lower than the line in the article’s figure. We checked it against the weighings themselves: our line follows the data more closely, so we publish it as it is.
What this chart does not cover
- Kittens under 8 weeks: there were too few weighings that young.
- Domestic shorthair cats with an adult weight of roughly 2 to 7 kg. Breeds such as the Maine Coon or the British Shorthair may grow differently.
- Kittens weighed before neutering: after neutering, weight often rises faster.
- Cats from US clinics and a research colony in the UK.
- Body condition: the chart compares weight only. Ask your vet or use the WSAVA chart.
How to track your kitten’s weight
WALTHAM suggests weighing every 2 to 4 weeks until 6 months, then every 1 to 3 months until your cat is fully grown. A kitchen scale works for a small kitten; later, weigh yourself holding the cat and subtract your own weight.
Compare the line, not one point, with the bands. If a weight falls outside them, check the date and the number, weigh again in two weeks, and ask your vet if you are concerned. A kitten that crosses two or more lines, or is unwell for a long time, should see the vet.
Frequently asked questions
How much should a kitten weigh at 8 weeks?
At 8 weeks, male kittens in the middle 82% of the data weigh 1.3–2.8 lb (0.57–1.28 kg) and females 1.4–2.7 lb (0.65–1.23 kg). That is where the chart starts: younger kittens were too few in the data.
How much should a 4-month-old kitten weigh?
At 4 months (17 weeks) males typically weigh 3.7–6.4 lb (1.69–2.91 kg) and females 3.3–5.3 lb (1.51–2.40 kg), with medians of 5.0 lb (2.27 kg) and 4.3 lb (1.94 kg).
Is my kitten too small?
A chart cannot say on its own. If the weight is below the lighter band or drops across lines, weigh again on the same scale and show the weights to your vet, who will also check body condition. Many healthy kittens sit near the edges of the band.
Does this chart work for Maine Coons?
Not well. It is built from domestic shorthair cats; large breeds such as the Maine Coon usually grow for longer and end up heavier. Use it as a rough guide only and ask your breeder or vet what to expect.
Sources and method
Data: Salt and colleagues, WALTHAM Petcare Science Institute (PLOS ONE, 2022): healthy intact domestic shorthair kittens with a normal body condition, from Banfield clinics in the USA and the WALTHAM research colony. The data are open under CC BY 3.0. Our fit used 6,254 weighings of 3,103 males and 7,961 weighings of 3,987 females.
Method: we fitted the data again the way the article describes (GAMLSS, males and females apart) and checked the result against its figures. For males the lines agree within about 3%. This is our fit of the open Waltham data, not the official WALTHAM chart.
Download the data
The weekly values behind this chart and table, in kilograms, as a CSV file. Free to reuse under CC BY 4.0 (opens in a new tab) with a link to this page and to the original article.
How to cite
Pettify. Kitten weight chart by week and month: our fit of the open Waltham growth data (Salt C et al., PLOS ONE 2022, doi:10.1371/journal.pone.0277531). https://pettifyapp.com/breeds/cats/kitten-weight-chart
Sources
- Salt C, German AJ, Henzel KS, Butterwick RF. PLOS ONE. Growth standard charts for monitoring bodyweight in intact domestic shorthair kittens from the USA. 2022. doi.org (opens in a new tab) (accessed )
- University of Liverpool Research Data Catalogue. Growth standard charts for monitoring bodyweight in Domestic Shorthair kittens: supporting data. 2021. doi.org (opens in a new tab) (accessed )
- WALTHAM Petcare Science Institute. WALTHAM Kitten Growth Charts. waltham.com (opens in a new tab) (accessed )
- WSAVA Global Nutrition Committee. Body Condition Score: cat. wsava.org (opens in a new tab) (accessed )