About CatYears

CatYears is a small, free calculator that answers one question properly: how old is your cat in human years? It exists because the answer most people grew up with — “multiply by seven” — is wrong at both ends of a cat’s life, and the better scale vets actually use deserves a clean, honest tool.

The numbers. The converter uses the feline life-stage scale published in the AAHA (American Animal Hospital Association) and AAFP (American Association of Feline Practitioners) life-stage guidelines: the first year of life ≈ 15 human years, the second year brings the total to ≈ 24, and each year after adds ≈ 4. Kitten months follow the month-by-month values from the same published chart; where the chart gives a range (11 months: 14–15), the site says so and uses the midpoint. The full method is laid out on the formula page.

The boundaries. An age equivalent is a comparison, not a health assessment. Individual cats age at different rates depending on breed, body condition, indoor or outdoor life and simple luck. CatYears does not diagnose anything, does not replace a veterinarian, and states its approximations where it makes them.

Who runs it. CatYears is built and maintained by Jimmy | ORBITFRAME, an independent web developer, as part of a family of small, single-purpose tools. Everything on the site runs in your browser — no accounts, no uploads, nothing to install.

Pro. A Pro tier ($9/mo) is planned — multiple-cat profiles, printable age certificates, vet-visit reminders — and is shown on the site as a preview only. No payment is taken and there is no sign-up yet.