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Kitten weight chart and growth checker

Is your kitten growing on track? Enter their age and weight to compare with typical growth, check the daily weight gain for young kittens, and get a rough adult-size estimate. Full kitten weight chart by week and month below.

Reviewed October 2026 · By Shoaib A. · See sources

Is my kitten a healthy weight?

Enter age and weight to compare with typical growth. Nothing is stored or sent anywhere.

Not sure? Use our kitten age calculator.
We'll check the daily gain. Young kittens should gain every day.
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Your kitten's growth check will appear here.
Typical range for the age, daily gain, and a rough adult-size estimate.

Quick answer

Kittens weigh about 100 g (3.5 oz) at birth and gain roughly 100 g a week, so a healthy kitten weighs about 450–550 g (1 lb) at 4 weeks and 850–950 g (2 lb) at 8 weeks. After that, growth varies more. About 3 kg (6.5 lb) at 6 months is average, and most cats reach their adult size of roughly 8–12 lb by about 12 months.

Key takeaways

  • Young kittens should gain weight every day, roughly 7–15 g a day (Kitten Lady).
  • A kitten under 8 weeks that stops gaining or loses weight is an urgent concern: call your vet (Kitten Lady).
  • The “1 lb per month” rule is a rough guide that gets less accurate after about 10 weeks (DiGangi et al., 2020).
  • Kittens reach about 80% of their adult size at around 30 weeks (VCA).
  • Most cats are fully grown by 12–18 months; Maine Coons can take 3–4 years (CFA).
  • For older kittens and adults, body shape (ribs easy to feel, a visible waist) matters more than the number on the scale.

0–8 weeks

Kitten weight chart by week

In the first 8 weeks, weight is the best single health check you have. Weigh at the same time every day with a kitchen scale that reads in grams, and look for a steady upward line.

Weight bands: Kitten Lady and PetMD. Daily gain minimums: Kitten Lady. ASPCA’s chart allows a wider, lower range, so a kitten slightly under these bands that is gaining steadily is often fine.
AgeTypical weight (g)Typical weight (oz / lb)Minimum daily gain
Birth75–115 g3–4 oz—
1 week150–250 g5–9 ozabout 7 g/day
2 weeks250–350 g9–12 ozabout 7–10 g/day
3 weeks350–450 g12–16 ozabout 10 g/day
4 weeks450–550 gabout 1 lbabout 10–12 g/day
5 weeks550–650 g1.2–1.4 lbabout 10–15 g/day
6 weeks650–750 g1.4–1.7 lbabout 10–15 g/day
7 weeks750–850 g1.7–1.9 lbabout 10–15 g/day
8 weeks850–950 gabout 2 lbabout 10–15 g/day

Kittens often roughly double their birth weight in their first 1–2 weeks (Kitten Lady). Sources disagree a little on exact bands: ASPCA’s chart, for example, gives 485–925 g at 8 weeks, a wider and lower range than Kitten Lady’s 850–950 g (ASPCApro chart). That’s why the daily trend matters more than any one number.

2–12 months

Kitten weight chart by month

After about 2 months, there is no single “correct” weight for each month. Breed, sex and genes all play a part. Use this as a rough guide and use body condition (below) as your main check.

A rough guide only. After about 10 weeks, healthy kittens vary a lot in weight, and males are usually heavier than females (DiGangi et al. 2020; Salt et al. 2022).
AgeRough guideNotes
2 monthsabout 2 lb (0.9 kg)End of the reliable weekly bands
3 monthsabout 3 lb (1.4 kg)“About 1 lb per month” rule (ASPCApro)
4 monthsabout 4 lb (1.8 kg)Growth spurt; males often pull ahead
5 monthsabout 5 lb (2.3 kg)Rule gets less accurate from here
6 monthsabout 6.5 lb (3 kg)Royal Canin average
7–8 monthsabout 75–80% of adult sizeVCA: about 80% of adult size at around 30 weeks
12 monthsmost cats 8–12 lb (3.6–5.4 kg)Adult size reached around 10–12 months for most cats; large breeds keep growing

In the WALTHAM/Banfield growth study of thousands of domestic shorthair kittens, male weights kept rising until about 10 months, while female weights levelled off just after 6 months (Salt et al., PLoS One 2022). Purina goes further and says there is no single “average” cat weight; it recommends checking body condition instead (Purina).

How big will my kitten get?

Can you predict a kitten's adult size?

There is no proven formula for predicting a kitten’s adult weight. You may see rules like “double the weight at 16 weeks”; we couldn’t find any vet or research source that backs them up.

What we do know: kittens reach about 80% of their adult size at around 30 weeks (about 7 months) and adult body size at around 40 weeks, according to VCA (VCA Animal Hospitals). Our checker uses that for a rough estimate between 30 and 40 weeks. PetMD suggests looking at the parents’ size if you know it (PetMD).

  • Most domestic cats: 8–12 lb (3.6–5.4 kg) as adults, with males usually larger (PetMD).
  • Females usually finish growing by about 10–12 months; males may keep growing until nearly 18 months (PetMD).
  • Maine Coons mature slowly, often not fully developed until 3–4 years; males typically 12–15 lb and females 9–12 lb (Cat Fanciers’ Association).

How to

How to weigh a kitten at home

  1. Under about 2 lb: use a digital kitchen scale that reads in grams. Put a small bowl or box on it, zero it, then pop the kitten in.
  2. Bigger kittens: weigh yourself, then weigh yourself holding the kitten, and subtract.
  3. Same time, same conditions: before a meal is best, so you’re not weighing a full tummy.
  4. Write it down. Daily under 8 weeks (Kitten Lady suggests at every feeding for the tiniest kittens), then every week or two (Kitten Lady).

Once you have the weight, the kitten feeding calculator turns it into daily calories and portions.

Body shape

Body condition score: the best check after 10 weeks

Vets use a 9-point body condition score (BCS). A 5 is ideal. Run your hands along your kitten’s sides and look from above:

Condensed from the WSAVA 9-point body condition score chart for cats.
ScoreWhat you feel and see
1–3 (too thin)Ribs, spine and hip bones easy to see; no fat you can feel; deep tuck at the belly
4Ribs easy to feel under very little fat; clear waist; slight belly tuck
5 (ideal)Well proportioned; ribs easy to feel under a thin layer of fat; waist visible behind the ribs; very little belly fat
6Ribs felt under slight extra fat; waist there but not obvious
7–9 (overweight)Ribs hard or impossible to feel; no waist; rounded belly with a fat pad

Royal Canin’s simple version: you should be able to feel the ribs without too much padding and see a waist from above (Royal Canin). See the full chart from WSAVA.

Be safe

When to worry about a kitten's weight

  • Under 8 weeks and not gaining, or losing weight: treat it as urgent and call your vet or foster coordinator (Kitten Lady). Research on newborn kittens found that failing to gain weight in the first two days was linked to a higher risk of death in the first two months (Mugnier et al., 2024).
  • Crossing growth lines: kittens that drop or jump across two or more growth-chart lines are more likely to be underweight or overweight as young adults (Salt et al., 2022).
  • Thin, with diarrhea, a pot belly or poor appetite: worms and other health problems can slow growth. See your vet.
  • Gaining fast after spay or neuter: energy needs drop, so ask your vet whether to trim portions.

Kitten weight questions

Usually about 850–950 g, or roughly 2 pounds. Some healthy kittens are a bit lighter. What matters most is that the kitten keeps gaining steadily.

Roughly 3 pounds (about 1.4 kg) is common, but healthy 3-month-old kittens vary quite a bit. Males are often heavier. Check body shape: ribs easy to feel and a visible waist.

In the first 8 weeks, most healthy kittens gain about 7–15 g a day. Kitten Lady’s minimums are about 7 g a day in the first two weeks rising to 10–15 g a day from 5 to 8 weeks.

About 3 kg (6.5 lb) is average according to Royal Canin, but the normal range is wide depending on sex and breed.

Most domestic cats end up about 8–12 lb. Kittens reach roughly 80% of their adult size at around 30 weeks, so weight at 7–8 months gives a rough idea. Large breeds like Maine Coons grow for years.

Most cats reach adult size between about 10 and 18 months. Females usually finish first; males may grow until about 18 months. Maine Coons may not be fully grown until 3–4 years.

For a kitten under 8 weeks that isn’t gaining, call your vet the same day. For older kittens, check that you’re feeding a complete kitten food in the right amount (try our feeding calculator) and book a vet check to rule out worms or illness.

Most domestic cats weigh about 8–12 lb (3.6–5.4 kg). Body condition is a better guide than weight alone: an ideal cat has ribs you can feel easily and a visible waist.

Sources