Cat Size Calculator
Enter your kitten's current weight and age, and choose whether it is a typical or a large breed type. You'll get an approximate adult weight range. Cats grow individually, so use it as a ballpark only.
Last updated: September 25, 2026
Frequently asked questions
How accurate is a kitten adult-size estimate?
Only roughly. Cats vary a lot, and mixed-breed kittens are especially hard to predict, so the range is intentionally wide.
How is this different from the Cat Age Calculator?
The Cat Age Calculator converts a cat's age into a human-year equivalent. This tool projects how heavy a growing kitten may become.
How is this different from the Cat BMI Calculator?
The Cat BMI Calculator computes a weight-to-length index from body measurements. This one uses age and current weight to estimate adult weight.
Can I use the dog size curve for cats?
No. Kittens grow on a different pattern from puppies, so this tool uses its own feline curve.
When do cats stop growing?
Most reach close to full size around 12 months, but many large breeds continue to mature for several more years.
Should I change my kitten's food because of the estimate?
No. Feed a diet suitable for growth as advised by your veterinarian, and do not restrict or increase food because of a size estimate.