Kitten Weight Chart Calculator — Week-by-Week Growth

Is your kitten growing on track? This calculator compares current body weight against expected weight-for-age ranges from birth through one year, using week-by-week growth curves built from Cornell Feline Health Center reference data. Slow gains in the first 8 weeks are the most reliable early warning for nutrition, parasite, or congenital issues — earlier intervention beats later treatment.

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Kitten's age (weeks)

Current weight (oz)

Use a kitchen scale. 1 lb = 16 oz. 1 oz ≈ 28 g.

Expected at week 8

28–40oz (avg 32)

Your kitten: 32 oz — ok

Reference chart

Week	Range (oz)	Avg
0	2.5–5	3.5
1	5–8	6
2	7–11	9
3	10–15	12
4	14–20	16
6	20–30	24
8	28–40	32
12	48–72	56
16	72–96	80
20	80–112	96
26	96–144	112
52	128–192	144

Weigh kittens daily for first 8 weeks — a healthy kitten gains ~0.25-0.5 oz per day. No weight gain 2 days in a row is a red flag.

Kitten growth terminology

Weaning: Transition from mother’s milk to solid food, typically 4-8 weeks of age.
FTT (failure to thrive): Kitten not gaining weight as expected; medical emergency in the first 8 weeks.
Fading kitten syndrome: Cluster of conditions causing rapid decline in neonates; requires immediate vet care.
Body condition: Visual + palpation grade; kitten BCS should stay between 4-5 throughout growth.

Frequently Asked Questions

How much should a 4-week-old kitten weigh?

Average 16 oz (1 lb), range 14-20 oz. Kittens double their birth weight by week 2 and triple by week 3-4. Weight gain of 0.25-0.5 oz per day is normal.

How much should a 2-month (8-week) kitten weigh?

Average 32 oz (2 lb), range 28-40 oz. At 8 weeks kittens are eating solid food and are typically ready for adoption.

When should I worry about kitten weight?

No weight gain for 2+ days in a row, weight below the bottom of the expected range, or weight loss. Causes: inadequate nursing/feeding, fading kitten syndrome, parasites, congenital issues. See vet immediately.

How do I weigh a kitten?

Digital kitchen scale (accurate to 0.1 oz). Place kitten in a bowl, tare scale, add kitten. Weigh daily at the same time (preferably morning).

Sources & References

[1]
Cornell Feline Health Center — Kitten Development — Cornell Feline Health Center
[2]
American Veterinary Medical Association — Pet Owner Resources — AVMA
[3]
AAHA (American Animal Hospital Association) Clinical Guidelines — AAHA

Common mistakes to avoid

Expecting every kitten in a litter to match — littermates can vary 15-20% in weight.
Underfeeding orphans — kittens under 4 weeks need KMR (kitten milk replacer), NOT cow milk (causes diarrhea).
Skipping daily weight check in the first 4 weeks — kittens can fade fast; a 2-day weight plateau is a red flag.

When to call the vet immediately

No weight gain for 24h in a kitten <4 weeks — emergency. Can indicate fading kitten syndrome, hypoglycemia, dehydration.
Weight loss at any age before weaning — vet urgent.

Pro tips

Newborn kittens should gain 10-15 g/day (0.35-0.5 oz). Miss 2 days = vet visit.
Use a kitchen scale (g resolution) until 8 weeks; then bathroom scale with you.
By week 8, kittens should weigh roughly 2 lb (900g) and be fully weaned.