Cat age chart: cat years to human years

On the veterinary life-stage scale, a cat is about 15 in human years at age 1, 24 at age 2, and gains roughly 4 human years per year after that — so a 10-year-old cat is about 56, and a 20-year-old about 96.

Every value below is generated from the same conversion the cat age calculator uses: the AAHA/AAFP life-stage scale. Kitten months follow the published month-by-month chart; the 11-month value is a 14–15 range on that chart, shown here at its midpoint of 14.5.

Kitten months

Kitten age	Human years	Life stage
1 month	1	Kitten
2 months	2	Kitten
3 months	4	Kitten
4 months	6	Kitten
5 months	8	Kitten
6 months	10	Kitten
7 months	11	Junior
8 months	12	Junior
9 months	13	Junior
10 months	14	Junior
11 months	14.5	Junior
12 months	15	Junior

Year by year, to 25 years

Cat age	Human years	Life stage
1 year	15	Junior
2 years	24	Junior
3 years	28	Prime
4 years	32	Prime
5 years	36	Prime
6 years	40	Prime
7 years	44	Mature
8 years	48	Mature
9 years	52	Mature
10 years	56	Mature
11 years	60	Senior
12 years	64	Senior
13 years	68	Senior
14 years	72	Senior
15 years	76	Geriatric
16 years	80	Geriatric
17 years	84	Geriatric
18 years	88	Geriatric
19 years	92	Geriatric
20 years	96	Geriatric
21 years	100	Geriatric
22 years	104	Geriatric
23 years	108	Geriatric
24 years	112	Geriatric
25 years	116	Geriatric

Reading the chart

Two features stand out. First, the early sprint: a cat covers the human equivalent of childhood and the teenage years in its first 24 months, which is why a 1-year-old can already be a parent. Second, the long plateau: from age 3 the steps settle into a steady 4-per-year rhythm, so middle-aged and older cats map almost linearly — a 7-year-old is about 44, a 12-year-old about 64, a 15-year-old about 76.

The chart is a comparison tool, not a health measurement. Individual cats age differently with breed, body condition, indoor or outdoor life and plain luck. For what each stage usually means for care, see the stage pages: Junior, Prime, Mature, Senior and Geriatric. The full method, including where the numbers come from, is on the method page.

Common questions

How old is a 3-year-old cat in human years?

About 28 — the first year on the steady 4-per-year part of the scale (24 + 4).

How old is the oldest cat on this chart?

The chart runs to 25 years, about 116 in human years. Cats do occasionally live past 25, and the same formula (24 + 4 × (age − 2)) extends to any age — the verified record holder, Creme Puff, reached 38.

Why does the chart start at months instead of years?

Because the first year changes too fast to summarise with one number: a 3-month-old kitten (≈4) and a 9-month-old (≈13) are at completely different developmental points.