Human years to cat years calculator
Enter a human age to see the cat age that matches it. Cats grow up fast in their first two years and then age at a steady pace, so the answer is not a simple multiple. A chart follows below.
- Old 7 to 1 rule
- 4.3
Human years to cat years chart
| Human age | Cat age (years) | 7 to 1 rule |
|---|---|---|
| 5 | 0.3 | 0.7 |
| 10 | 0.7 | 1.4 |
| 13 | 0.9 | 1.9 |
| 15 | 1.0 | 2.1 |
| 18 | 1.3 | 2.6 |
| 20 | 1.6 | 2.9 |
| 21 | 1.7 | 3.0 |
| 25 | 2.3 | 3.6 |
| 30 | 3.5 | 4.3 |
| 40 | 6.0 | 5.7 |
| 50 | 8.5 | 7.1 |
| 60 | 11 | 8.6 |
| 70 | 14 | 10 |
| 80 | 16 | 11 |
How it works
This is the reverse of the cat years to human years calculator. That calculator uses the commonly cited veterinary guideline: 15 human years for a cat's first year, 24 at age two, and 4 more for each year after. Here we find the cat age whose human equivalent matches the age you enter.
24 human years = 2 cat years
after that, every 4 human years = 1 more cat year
The old rule of one cat year for every seven human years is popular but crude, and it is shown only for comparison.
Questions
How old am I in cat years?
At 30 human years you match a cat of about 3.5 years. The old 7 to 1 rule would say about 4.3.
How old is a 13 year old in cat years?
About 0.9 years. A cat reaches the equivalent of 15 human years at its first birthday.
Is a cat year really seven human years?
No. Cats mature very quickly in their first two years and then age more slowly, so the chart above is closer to reality than multiplying by seven.
What about dogs?
Dogs age at different speeds by size. See human years to dog years.
Sources
- American Veterinary Medical Association (AVMA), guidance on converting a cat's age to human years (15 for year one, 24 for year two, 4 per year after).
Last reviewed 2026-10-26.