Kitten Size Calculator
Enter your kitten's weight now, its age and whether it is a large breed. The calculator uses typical growth curves to estimate its adult weight and a likely range.
- Adult weight
- Likely range
- Size
Weigh the kitten on kitchen scales in a box, then take away the box.
At 16 weeks most kittens weigh about half their adult weight. A 1.8 kg kitten at 16 weeks should be about 4 kg as an adult cat, likely between 3.4 and 4.6 kg. That is an average sized cat.
Kitten growth chart
Average domestic cat. Search for an age.
| Age | Typical weight | Share of adult |
|---|---|---|
| 8 weeks | 0.9 kg | 22% |
| 12 weeks | 1.35 kg | 33% |
| 16 weeks | 1.8 kg | 45% |
| 20 weeks | 2.25 kg | 55% |
| 6 months | 2.8 kg | 70% |
| 9 months | 3.4 kg | 83% |
| 12 months | 4 kg | 100% |
kg.
Age and adult weight
Typical kitten. Slide the age.
Kitten and grown cat drawn side by side.
How to estimate adult size
Kitten to cat. Step through it.
Weigh
On kitchen scales.
Weigh weekly and track the trend, not one reading.
Small, average or large breed
Cat sizes. Compare them.
Singapura, Devon Rex.
Domestic shorthair.
Maine Coon, Ragdoll.
Large breeds keep growing until 3 or 4 years old.
Healthy growth
Kitten checks. Tick each item.
Tick each item as you go.
Ask your vet if the kitten stops gaining weight.
What you get
Kitten sizing. Each tile explains one result.
Estimate.
Likely spread.
Weeks and months.
Logged.
Small to large.
Neutered cats often gain weight, so watch portions.
Frequently Asked Questions
No question matches that search.
How big will my kitten get?
Roughly double its weight at four months, for most domestic cats.
When do kittens stop growing?
Most reach full size at about twelve months, large breeds later.
How much should a kitten gain each week?
About one hundred grams a week for the first six months.
Can paw size tell how big a kitten will be?
Only loosely. Weight and breed are better guides.
Do male cats grow bigger?
Usually, males are often a little heavier than females.
Is this accurate for mixed breeds?
It gives a fair guide, but genes can make any cat bigger or smaller.
Watch them grow
Weigh your kitten now and then and see roughly how big your cat will be.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.