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Cat Years Calculator – Cat Age in Human Years

Use this cat years calculator to convert your cat’s age to human years and see which life stage it is in.

My tools →
Animal
years
months
Size (adult weight)

Small < 9 kg (20 lb) · medium 9–23 kg · large 23–41 kg · giant > 41 kg (90 lb)

Human years

–

Based on DNA methylation research in Labrador retrievers (UC San Diego, 2019). It ages young dogs faster than the classic chart.

Runs in your browser – your data never leaves your device Also available via our free API

Cat age chart in human years

Animal age Human years
1 year 15
2 years 24
3 years 28
4 years 32
5 years 36
6 years 40
7 years 44
8 years 48
9 years 52
10 years 56
11 years 60
12 years 64
13 years 68
14 years 72
15 years 76
16 years 80
17 years 84
18 years 88
19 years 92
20 years 96

How to use the Cat Years Calculator

  1. 1 Choose the animal.
  2. 2 Enter its age in years and months (for dogs, also pick the size).
  3. 3 Read the age in human years and the matching life stage.

How cats age

Kittens grow up remarkably fast. By their first birthday cats are roughly equivalent to a 15-year-old human, and by two they are about 24 – a young adult. After that, every cat year counts as about four human years. A 12-year-old cat is therefore roughly 64 in human terms.

Feline life stages

Veterinary guidelines describe four life stages for cats:

  • Kitten – birth to 1 year
  • Young adult – 1 to 6 years
  • Mature adult – 7 to 10 years
  • Senior – over 10 years

Indoor cats commonly live 12 to 18 years, and many reach their twenties. A 20-year-old cat is the equivalent of a 96-year-old person.

Caring for an older cat

Senior cats hide pain well. Regular vet check-ups help catch common age-related conditions such as kidney disease, an overactive thyroid and arthritis early. Easy access to litter trays, water and warm resting places makes life more comfortable for an older cat.

Frequently asked questions

How old is a 1-year-old cat in human years?

About 15 human years – comparable to a teenager.

How old is a 15-year-old cat in human years?

About 76 human years.

Do indoor and outdoor cats age differently?

They age at the same rate, but indoor cats usually live longer because they face fewer risks such as traffic and infections.

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