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Cat Age Calculator: Cat Years to Human Years
Enter your cat’s age and see the human-year equivalent from two published tables, plus the life stage vets use.
Whole numbers. A 7-month-old kitten is 0 years and 7 months.
Enter your cat’s age and press Calculate. You will see the human-year equivalent from two published tables, and the life stage the vet guidelines put your cat in.
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- Two published tables
- AAHA/AAFP life stages
- Maine Coon note
A 1-year-old cat is about 15 or 16 human years and a 2-year-old about 21 to 24; after that each cat year adds about four. The two published tables differ slightly: International Cat Care uses 15 and 24, Cornell’s Feline Health Center uses 16 and 21. Both reject the old rule of seven human years per cat year.
Cat years to human years chart
The calculator above interpolates month by month. This is the yearly version of both tables.
| Cat age (years) | Human years: International Cat Care | Human years: Cornell | AAHA/AAFP stage |
|---|---|---|---|
| 1 | 15 | 16 | Young adult |
| 2 | 24 | 21 | Young adult |
| 3 | 28 | 25* | Young adult |
| 4 | 32 | 29* | Young adult |
| 5 | 36 | 33* | Young adult |
| 6 | 40 | 37* | Young adult |
| 7 | 44 | 41* | Mature adult |
| 8 | 48 | 45* | Mature adult |
| 9 | 52 | 49* | Mature adult |
| 10 | 56 | 53 | Senior |
| 11 | 60 | 57* | Senior |
| 12 | 64 | 61 | Senior |
| 13 | 68 | 65* | Senior |
| 14 | 72 | 69* | Senior |
| 15 | 76 | 73 | Senior |
| 16 | 80 | 77* | Senior |
| 18 | 88 | 85* | Senior |
| 20 | 96 | 93* | Senior |
* Cornell publishes figures for ages 1, 2, 10, 12 and 15. The other rows apply its rule of about four human years for every cat year after 2. International Cat Care lists every year; the rows here match its table. Read 27 October 2026.
Why the two tables disagree
They agree on the slope (four human years per cat year after the second birthday) and differ on where it starts. International Cat Care gives 24 at age 2, Cornell gives 21, so the gap is three years early on and stays at three: a 10-year-old cat is 56 on one table and 53 on the other, and a 15-year-old is 76 against 73. Neither is a measurement of a particular cat. Both are rules of thumb for how a typical cat’s development compares with a person’s.
Cat life stages
Vets use stages more than human equivalents. The 2021 AAHA/AAFP guidelines define four age-based stages plus an end-of-life stage that can apply at any age. International Cat Care splits the same span into more steps.
| Source | Kitten | Adult stages | Older stages |
|---|---|---|---|
| AAHA/AAFP 2021 | Birth to 1 year | Young adult 1 to 6 years; mature adult 7 to 10 years | Senior 10 years and older; end of life at any age |
| International Cat Care | 0 to 6 months | Junior 7 months to 2 years; adult 3 to 6 years; mature 7 to 10 years | Senior 11 to 14 years; super senior 15 years and over |
Do Maine Coons age differently?
The Cat Fanciers’ Association describes the breed as slow-maturing and says it can take up to three years to reach full growth. That is about size, not about the human-age conversion: neither table above gives a breed-specific figure, so a 2-year-old Maine Coon is still treated as a 2-year-old cat even though it may not have finished growing. For how long the breed lives, see the Maine Coon lifespan guide, which uses veterinary death records, and for size by age see the Maine Coon growth chart.
How this calculator works
It converts your cat’s age to months. Up to 24 months it moves between the points in International Cat Care’s table (for example 7 months is 12 human years, 12 months is 15, 18 months is 21); after 24 months it adds four human years for each further year. The Cornell figure starts at 1 year (16), reaches 21 at 2 years and then adds four per year; Cornell gives no figure for under a year. Life stage uses whole years: AAHA/AAFP calls under 1 a kitten, 1 to 6 young adult, 7 to under 10 mature adult, and 10 and over senior.
Questions
Is one cat year really seven human years?
No. Cornell’s Feline Health Center says the seven-year rule is not entirely accurate: a one-year-old cat is physiologically like a 16-year-old person and a two-year-old like a 21-year-old, with about four human years for each year after that.
How old is a 10-year-old cat in human years?
About 56 on International Cat Care’s table and 53 on Cornell’s. Under the AAHA/AAFP 2021 guidelines a 10-year-old is at the line between mature adult and senior.
When does a cat count as a senior?
AAHA/AAFP 2021 puts seniors at 10 years and older. International Cat Care starts senior at 11 and adds a super senior stage from 15.
How long does a Maine Coon take to grow up?
The Cat Fanciers’ Association says up to three years to reach full growth, so size can lag behind age for longer than in many breeds.
More cat calculators
Related guides
- Maine Coon lifespan: what the vet records show
- Maine Coon growth chart
- How big do Maine Coon cats get
- Best food for a Maine Coon
Sources
- International Cat Care, “How to tell your cat’s age in human years”, table of ages and life stages, read 27 October 2026.
- Cornell University Feline Health Center, “The Special Needs of the Senior Cat”, read 27 October 2026.
- AAHA/AAFP Feline Life Stage Guidelines, published February 2021, catvets.com/life-stage and aaha.org, read 27 October 2026.
- Cat Fanciers’ Association, Maine Coon breed page (“slow-maturing breed that can take up to three years to reach full growth”), read 27 October 2026.
General information, not veterinary advice. Cat-to-human age is a rule of thumb; ask your vet about your own cat’s health and stage of life.