Cat Years to Human Years — Conversion Chart & Life Stages

Want the answer for your own cat, months included? Use the pet age calculator.

How cat years work

Cats mature very fast at first, then settle into a steady rate. The conversion used by International Cat Care (and echoed by Purina): the first cat year equals about 15 human years, two cat years equal about 24, and every year after that adds about 4 human years. Unlike dogs, size barely matters — most cats are cat-sized.

Cat age chart

Cat years → human years (15 / 24 / +4 rule)
Cat age	Human years	Cat age	Human years
1	15	11	60
2	24	12	64
3	28	13	68
4	32	14	72
5	36	15	76
6	40	16	80
7	44	17	84
8	48	18	88
9	52	19	92
10	56	20	96

Beyond 20, keep adding 4 per year — a 25-year-old cat is around 116 human years, which is why they're rare and famous.

Feline life stages

The 2021 AAHA/AAFP Feline Life Stage Guidelines define four stages:

2021 AAHA/AAFP feline life stages
Stage	Cat age	Human-equivalent
Kitten	0–1 year	0–15
Young adult	1–6 years	15–40
Mature adult	7–10 years	44–56
Senior	over 10 years	60+

From the mature-adult stage on, vets generally recommend more frequent checkups — aging cats hide illness well, and "senior" is a screening signal, not a verdict.

Also: dog years to human years.

Cat age	Human years	Cat age	Human years
1	15	11	60
2	24	12	64
3	28	13	68
4	32	14	72
5	36	15	76
6	40	16	80
7	44	17	84
8	48	18	88
9	52	19	92
10	56	20	96

Cat age	Human years	Cat age	Human years
1	15	11	60
2	24	12	64
3	28	13	68
4	32	14	72
5	36	15	76
6	40	16	80
7	44	17	84
8	48	18	88
9	52	19	92
10	56	20	96

Cat age	Human years	Cat age	Human years
1	15	11	60
2	24	12	64
3	28	13	68
4	32	14	72
5	36	15	76
6	40	16	80
7	44	17	84
8	48	18	88
9	52	19	92
10	56	20	96