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Kitten growth chart
Healthy kittens weigh about 100 g at birth, gain roughly 10–15 g a day, and reach about 1 lb by 4 weeks and 2 lb by 8 weeks. Check your kitten's weight below, or find its age in the charts.
You'll see whether your kitten's weight is in the usual range for its age.
Ranges are typical, not targets. Kittens that eat well and gain steadily are usually fine even near the edges. Last reviewed October 7, 2026.
Kitten weight chart by week (0–8 weeks)
Weekly ranges from the ASPCA kitten age and weight chart, which assumes kittens gain 7–15 g a day. Newborn kittens usually weigh 50–150 g (about 2–5 oz).
| Age | Weight (grams) | Weight (ounces) |
|---|---|---|
| Week 1 | 70–190 g | 2.5–6.7 oz |
| Week 2 | 149–295 g | 5.3–10.4 oz |
| Week 3 | 198–400 g | 7.0–14.1 oz |
| Week 4 | 247–505 g | 8.7–17.8 oz |
| Week 5 | 296–610 g | 10.4–21.5 oz |
| Week 6 | 345–715 g | 12.2–25.2 oz |
| Week 7 | 394–820 g | 13.9–28.9 oz |
| Week 8 | 443–925 g | 15.6–32.6 oz |
Kitten weight chart by month
After 8 weeks kittens are usually weighed in pounds. These are the typical weights in Purina's kitten feeding chart:
| Age | Typical weight |
|---|---|
| 4–12 weeks (1–3 months) | 1–3 lb (0.5–1.4 kg) |
| 12–24 weeks (3–5.5 months) | 3–5 lb (1.4–2.3 kg) |
| 24–36 weeks (5.5–8 months) | 5–7 lb (2.3–3.2 kg) |
| 36–52 weeks (8–12 months) | 5–14 lb (2.3–6.4 kg) |
How fast do kittens grow?
- Birth: about 100 g. Vets use 100 g ± 10 g as a healthy newborn weight.
- First weeks: a gain of about 10–15 g a day. Most kittens double their birth weight within the first 1–2 weeks.
- 4 weeks: about 1 lb. 8 weeks: about 2 lb. 10 weeks: about 2.5 lb. The ASPCA uses these milestones to estimate the age of kittens up to about 10 weeks.
- 1 year: most cats are adult size. Large breeds such as the Maine Coon can keep growing until about 2 years.
The average adult house cat weighs about 8–12 lb (3.6–5.4 kg). To see if your grown cat is at a healthy weight, use the cat weight calculator.
Weigh young kittens daily for the first two weeks, then every few days. A kitten that stops gaining, loses weight, or won't eat needs to see a vet the same day: kittens have very little reserve.
Sources
ASPCA Kitten Age & Weight Chart (2023); ASPCApro, How to determine a kitten's age; Merck Veterinary Manual, Management of the neonate in dogs and cats; PetMD, average cat weight and when cats stop growing; Purina kitten feeding chart.
Questions people ask
How much should an 8-week-old kitten weigh?
About 2 lb (roughly 900 g). The ASPCA chart gives a range of 443–925 g for week 8.
How much should a 3-month-old kitten weigh?
Usually about 3 lb, at the boundary between Purina's 1–3 lb and 3–5 lb bands.
How much should a 6-month-old kitten weigh?
Typically around 5–7 lb, depending on sex, breed and how big the parents are.
How much weight should a kitten gain per day?
About 10–15 g a day in the first weeks of life. The ASPCA chart is built on a gain of 7–15 g a day.
When do kittens stop growing?
Most cats reach adult size at about 12 months. Some large breeds, such as Maine Coons, keep growing until about 2 years.