CollarCat Age Calculator: Cat Years to Human Years
How old is your cat in human years? Convert her age with the standard feline aging formula and see which life stage she is in.
Cat Age Calculator
Enter your cat's age to convert it into human years.
How to Calculate Cat Years in Human Years
The “one cat year equals seven human years” rule is a myth. Cats grow up fast, then age gently. Veterinarians use this formula instead:
- Year 1 counts as about 15 human years.
- Year 2 adds about 9 more (roughly 24 human years by age 2).
- Each year after adds about 4 human years.
Human age ≈ 15 + 9 + (cat years − 2) × 4
Cat Life Stages
The AAHA and AAFP feline guidelines group a cat's life into four stages: kitten (up to 1 year), young adult (1 to 6), mature adult (7 to 10), and senior (over 10 years).
Enter her age
Give your cat's age in years or months.
Convert
The calculator applies the standard feline formula.
See her human age
Get her age in human years and her life stage.
Cat Age to Human Age Chart
A quick conversion using the standard feline aging formula.
| Cat age | Human years | Cat age | Human years |
|---|---|---|---|
| 1 year | 15 | 9 years | 52 |
| 2 years | 24 | 10 years | 56 |
| 3 years | 28 | 11 years | 60 |
| 4 years | 32 | 12 years | 64 |
| 5 years | 36 | 13 years | 68 |
| 6 years | 40 | 14 years | 72 |
| 7 years | 44 | 15 years | 76 |
| 8 years | 48 | 16 years | 80 |
Frequently Asked Questions
Answers to the most common questions about your cat's age.
The standard feline formula counts the first year of a cat's life as about 15 human years and the second year as about 9 more, reaching roughly 24 human years by age 2. After that, each cat year adds about 4 human years. So a 5-year-old cat is about 36 in human years.
No, that is a myth. Cats mature very quickly in their first two years, then age more slowly. That is why the first year alone counts for about 15 human years and each later year for only about 4.
Using the AAHA and AAFP feline life stages, a cat is a kitten up to 1 year, a young adult from 1 to 6 years, a mature adult from 7 to 10 years, and a senior once over 10 years old.
Indoor cats typically live around 13 to 17 years, and many reach their late teens or even 20 or more with good care. Outdoor cats tend to have shorter lifespans due to greater risks.
Sources & Further Reading
The formula and life stages on this page reflect published veterinary guidelines. To go deeper, visit these trusted references: