Convert your cat age to human years — with life stage, next-birthday age and an estimate of remaining senior years.
Months beyond the whole years above; values of 12 or more are folded into years automatically.
How to use this tool
Whole years plus any extra months — a 1-year-6-month cat is not the same as a 1-year-old.
Under Advanced options, lifestyle adjusts the lifespan guidance shown with your result.
The big number is the human-year equivalent, with the life stage and the age at the next birthday underneath.
Life stages hint at care needs — seniors benefit from more frequent vet visits — but every cat ages at its own pace.
Formula & worked example
Worked example: a 3-year-old cat is 24 + 4 = 28 in human years. A 10-year-old cat is 24 + 4 × 8 = 56. A 6-month-old kitten is halfway through its first year, so 15 × 0.5 = 7.5 human years.
Limitations — read this before you rely on it
Cat-to-human age charts are population averages, not precise biology: breed, size, health and lifestyle all shift the pace, and the popular 7-times rule is simply wrong for cats. Treat the result as a rough guide, and ask a vet about your own cat health decisions.
Frequently asked questions
Use the standard rule: the first cat year equals 15 human years, the second adds 9 (24 total), and each year after adds about 4. So a 5-year-old cat is roughly 36 in human years.
Because cats mature far faster than humans early on: a one-year-old cat is already a young adult, not a 7-year-old child. The 15 + 9 + 4 rule matches real development much better.
Kitten (under 1 year), junior (1–2), prime (3–6), mature (7–10), senior (11–14) and geriatric (15+). This calculator shows the stage for the age you enter.
On average, yes — indoor cats commonly reach 13–17 years, while outdoor cats face traffic, disease and fights and average far less. Individual cats vary enormously either way.
From about 11 years. Senior cats benefit from vet checks every 6–12 months, weight and dental monitoring, and diets suited to older kidneys and joints — ask your vet what fits your cat.