Cat years to human years

Forget the old "age × 7". Here's the conversion matching International Cat Care's published table, with the AAHA/AAFP life stages.

Your cat's age

Cat's age3 years

6 months10 years25 years

In human years, that's about

28 years

Young adult

Estimated using the AAHA/AAFP veterinary guidelines. Every cat ages at their own pace (genetics, lifestyle, health).

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How a cat's age is calculated

Cats don't age in a straight line. They grow at full speed early on, then their clock slows down. The rule below matches the age table published by International Cat Care (we checked: the AAHA/AAFP guidelines themselves contain no conversion chart, whatever other sites claim):

The 1st year equals about 15 human years.
The 2nd year adds 9 more: a 2-year-old cat is about 24 in human years.
Every year after that counts for roughly 4 human years.

These numbers are averages. Breed, lifestyle (indoor/outdoor), spaying or neutering and health all shift the actual pace.

Cat age to human age conversion chart

Cat's age	Human age	Life stage
6 months	10 years	Kitten
1 year	15 years	Young adult
2 years	24 years	Young adult
3 years	28 years	Young adult
4 years	32 years	Young adult
6 years	40 years	Young adult
8 years	48 years	Mature adult
10 years	56 years	Mature adult
12 years	64 years	Senior
15 years	76 years	Senior
18 years	88 years	Senior
20 years	96 years	Senior

A cat's 4 life stages

Kitten

0 to 1 year

Very fast growth and socialization.

Young adult

1 to 6 years

Peak shape, at their physical and mental best.

Mature adult

7 to 10 years

Watch their weight and start regular checkups.

Senior

over 10 years

Closer veterinary monitoring (kidneys, thyroid, joints).

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Frequently asked questions

+How many human years is 1 cat year?

About 15 years. A cat grows incredibly fast in its first year: it already reaches the equivalent of a human teenager.

+Is the "age × 7" rule accurate?

No. It's too simplistic: it underestimates the lightning-fast maturing of the first two years and overestimates aging after that. The 15 / 24 / +4 rule is much closer to reality.

+At what age is a cat considered senior?

Past 10 years, per the AAHA/AAFP guidelines. But some cats over 10 stay in excellent shape: your vet is the one to judge, case by case.