Cat Age Calculator
Convert cat years to human years with the formula vets use, see your cat's life stage, and find out what to expect at each age — from zoomies to dignified retirement.
Use decimals for kittens — e.g. 0.5 = 6 months
Affects typical lifespan, not the age math
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You might also need:Kitten Age Calculator·Dog Age Calculator
The cat years formula
every year after = +4 human years
Cats mature at lightning speed: a 6-month-old kitten is like a 10-year-old child, and a one-year-old cat is a teenager. After age two, feline aging settles to a steady 4 human years per calendar year — remarkably consistent across breeds, unlike dogs.
Cat years to human years chart
| Cat age | Human years | Life stage |
|---|---|---|
| 6 months | 10 | Kitten |
| 1 | 15 | Junior |
| 2 | 24 | Junior |
| 4 | 32 | Prime |
| 7 | 44 | Mature |
| 10 | 56 | Mature |
| 12 | 64 | Senior |
| 15 | 76 | Geriatric |
| 20 | 96 | Geriatric |
Care by life stage
- Kitten (0–1): rescued a stray and unsure of their age? The kitten age calculator estimates it from weight and teeth.
- Prime (3–6): keep weight in check — portion properly with the cat food calculator; indoor cats gain weight easily.
- Senior (11+): twice-yearly vet visits with bloodwork; kidney disease and hyperthyroidism are common and very manageable when caught early.
Frequently asked questions
How do you convert cat years to human years?+
The veterinary formula: a cat’s first year equals about 15 human years, the second adds 9 (a 2-year-old cat is ~24), and every year after adds 4. So a 10-year-old cat is about 56 in human years.
How old is a 12-year-old cat in human years?+
About 64 human years — comfortably retired, opinionated about dinner time, and entitled to the warmest spot in the house.
Do indoor and outdoor cats age differently?+
The aging formula is the same, but lifespans differ dramatically: indoor cats typically live 12–18 years (many reach 20), while outdoor cats average far shorter due to hazards. An indoor lifestyle is the single biggest longevity boost you can give a cat.
When is a cat considered a senior?+
Vets consider cats senior from about 11 years (60 in human years), and geriatric from 15 (76+). From 11, twice-yearly checkups with kidney and thyroid bloodwork catch the common age-related issues early.
What is the oldest cat ever recorded?+
Creme Puff of Austin, Texas lived to 38 years and 3 days — roughly 168 in human years. Most cats don’t read record books, but 20+ is increasingly common for indoor cats with good vet care.