Cat Age Calculator
Your cat's age in human years, on the chart vets use.
Converting cat years
Slide to your cat's age and read the human equivalent with its life stage. The chart is the veterinary convention: 15 human years at one, 24 at two, then about four per year — so a 10-year-old cat sits around 56, and the venerable 20-year-old at 96.
Cats plateau; dogs diverge
Unlike dogs, size barely matters for cats — they converge on one curve: explosive maturing for two years, then a steady plateau. Indoor cats routinely reach their late teens (outdoor life is statistically much harsher), "senior" begins around 11, and the record — Creme Puff of Texas, 38 — maps to an absurd 168 human years.
A cat's real biological age shows in teeth, muscle, kidneys and bloodwork, which is what vets actually assess; the chart is a translation for humans, not medicine. The dog version adds the size classes dogs need, and for the humans in the household the age calculator counts to the day.
Frequently asked questions
How old is my cat in human years?
15 at one, 24 at two, then add four per year: a 6-year-old cat is about 40, a 12-year-old about 64.
When is a cat considered a senior?
Around 11 cat years (~60 human), with 15+ counted geriatric. Twice-yearly vet checks are the standard advice from the senior stage.
Do indoor cats really live longer?
Substantially — indoor cats commonly reach 15-18, while outdoor life brings cars, fights and disease that pull the average far lower.
Does breed or size change cat ageing?
Far less than in dogs — cats converge on one curve, which is why this chart has no size classes.