Kitten weight chart by age

A healthy kitten gains fast and predictably: about 18% of adult weight by 8 weeks, 30% by 12 weeks, 40% by 16 weeks, and reaches adult weight at around 12 months. For a cat that will weigh 4.5 kg, that is roughly 0.8 kg at 8 weeks and 1.8 kg at 16 weeks. The number on the scale matters less than the trend — a kitten that is gaining steadily is doing fine, whatever the absolute figure.

Weight is one of four checks on a growing kitten (the others: body condition, appetite, and how it behaves). This page is the chart for the first one.

Table 1: share of adult weight, by age

Because adult size varies so much between cats, the useful measure is the share of adult weight already reached:

Age	Share of adult weight	If adult weight is 4.5 kg	Daily food	Dry food (cups)
Birth	~3%	0.10 kg	— kcal	— cups
4 weeks	~9%	0.40 kg	— kcal	— cups
8 weeks	18%	0.80 kg	148 kcal	0.31 cups
12 weeks (3 months)	30%	1.35 kg	219 kcal	0.46 cups
16 weeks (4 months)	40%	1.80 kg	218 kcal	0.46 cups
6 months	60%	2.70 kg	295 kcal	0.62 cups
9 months	80%	3.60 kg	366 kcal	0.77 cups
12 months	100%	4.50 kg	260 kcal	0.55 cups

Weight shares follow the usual clinical growth pattern for domestic kittens. Daily food is 70 × kg^0.75 × the life-stage multiplier — 2.5× under 4 months, 2× from 4–12 months, then the adult figure (1.2× for a neutered indoor cat). Cups assume a dry food at 3,800 kcal/kg and 125 g per cup. These are averages: a kitten that is smaller or larger than the reference at every weigh-in is still normal.

Table 2: what that looks like in kilograms

Reference figures for three adult sizes. Find the size your cat is expected to reach, then read down the column:

Age	Adult 3.5 kg	Adult 4.5 kg	Adult 6 kg
8 weeks	0.63 kg	0.81 kg	1.08 kg
12 weeks	1.05 kg	1.35 kg	1.80 kg
16 weeks	1.40 kg	1.80 kg	2.40 kg
6 months	2.10 kg	2.70 kg	3.60 kg
9 months	2.80 kg	3.60 kg	4.80 kg
12 months	3.50 kg	4.50 kg	6.00 kg

Why 16 weeks is not more than 12 weeks. Look closely at the daily column and the figures barely move between 12 and 16 weeks. That is not a plateau: the multiplier changes at four months, from 2.5× resting energy to 2×. The kitten keeps growing, but its energy need per kilogram falls as it leaves the fastest growth phase. The total starts climbing again from six months. If you are feeding the amount that matches the age band, you are doing it right — do not push extra food in at four months because the number stopped rising.

How to weigh a kitten at home

Kitchen scale, weekly. Weigh at the same time of day, ideally before a meal.
Too wriggly for the scale? Weigh yourself holding the kitten, then subtract your own weight.
Weekly for the first six months is the useful interval — daily is noise, monthly misses the trend.
Then monthly until a year, and after that treat it as an adult (see body condition score).

The trend beats the number

Two things matter more than any single figure on this chart:

Steady growth. A kitten tracking its own curve, even a low one, is generally fine. A kitten that stops gaining, or loses weight, is a veterinary question.
Body condition alongside the scale. Weight alone can’t tell muscle from fat, or a big frame from an overweight one. Use the waist and rib checks at every weigh-in.

When to call the vet: no weight gain over two consecutive weeks in a kitten under six months, any weight loss, or a kitten that is eating less while also not growing. Those are reasons to be seen, not to adjust the food.

Feeding is a separate calculation

The daily figures in Table 1 come from the same equation used across this site; the amount you actually put down should come from the cat portion calculator, which takes your kitten’s current weight and your food’s calories. For the meal schedule itself, see kitten feeding by age. To convert the amount into scoops, see cups in a pound of cat food.

Common follow-up questions

My kitten is much smaller than the chart. Is that wrong? Not necessarily — the chart is an average across all cats. What matters is that your kitten is gaining week on week. A consistently small but steadily growing kitten is usually just a small cat.

When should I stop feeding kitten food? Most cats move to adult food around 12 months, or when they reach adult weight. See kitten feeding by age.

Is a big kitten going to be a big cat? Broadly yes, but growth rate early on is not a precise predictor of adult size — breed and genetics matter more. Use the trend for health, not for forecasting.

Weighing a wriggly kitten? A gram kitchen scale on Amazon is the cheapest piece of equipment that makes a growth chart actually useful — weekly weights beat eyeballing every time.

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Sources: the energy equation follows the National Research Council’s Nutrient Requirements of Dogs and Cats (2006); the life-stage multipliers (2.5× under four months, 2× from four to twelve) are the same ones used on this site’s kitten pages, and the weight-share pattern follows the usual clinical growth curve. Body condition framing follows the WSAVA Global Nutrition Committee guidelines. This page is general information, not veterinary advice.

Kitten feeding by age → · Cat portion calculator → · Cat body condition → · Cups in a pound →