Cat Age Calculator: your cat’s age in human years
A cat is about 15 in human years at one and 24 at two, then ages about 4 human years each year. Enter your cat’s age for the number, the life stage it is in, and how often it should see the vet.
Enter your cat’s age above for its age in human years. (The live result needs JavaScript; with it off, use the chart below.)
Cat years to human years: the chart
| Cat’s age | Human years |
|---|---|
| 1 month | 1 |
| 3 months | 4 |
| 6 months | 10 |
| 1 year | 15 |
| 2 years | 24 |
| 3 years | 28 |
| 5 years | 36 |
| 7 years | 44 |
| 10 years | 56 |
| 12 years | 64 |
| 15 years | 76 |
| 18 years | 88 |
| 20 years | 96 |
These values come from International Cat Care’s age chart and the Feline Life Stages chart from FelineVMA, which carries the AAHA logo; the two agree wherever both give a value. Between the chart’s rows, the calculator fills in the steps evenly, so a result for, say, nine months is an estimate.
Why the first two years count for so much
A kitten goes from newborn to grown-up in about a year, so the first year is worth roughly 15 human years and the second brings a cat to about 24, a young adult. After that the pace settles to about four human years for every cat year. The old “times seven” rule gets both halves wrong: it makes young cats too young and old cats too old.
The four life stages (AAHA/AAFP, 2021)
- Kitten: birth up to 1 year.
- Young adult: 1 to 6 years.
- Mature adult: 7 to 10 years.
- Senior: 10 years and older.
The guidelines add an end-of-life stage that can come at any age. Every stage needs a full checkup at least once a year, and senior cats at least every six months. Between visits, note any change in weight, thirst, appetite or litter-box habits so your vet has more to go on. For a senior, the free senior cat quality-of-life tracker helps you notice those changes between visits.
Frequently asked questions
- Is one cat year really seven human years?
- No. Cats grow up far faster than that at the start: a one-year-old cat is about 15 in human years and a two-year-old about 24, according to the charts from International Cat Care and the AAHA-endorsed Feline Life Stages chart. After that, each cat year adds about four human years.
- How do I calculate my cat’s age in human years?
- Count the first year as 15, the second as 9 more (24 in total), and then add 4 for every year after that. A 10-year-old cat is about 56 in human years, a 15-year-old about 76 and a 20-year-old about 96.
- When is a cat a senior?
- The 2021 AAHA/AAFP Feline Life Stage Guidelines count a cat as senior from 10 years old. Other groups draw the line a little differently: International Cat Care calls 11 to 14 senior and 15 and over super senior. Either way, it is a good time to move to checkups every six months.
- How often should my cat see the vet?
- At least once a year at every life stage, and at least every six months once your cat is a senior, according to the AAHA/AAFP guidelines. Kittens need more visits in the first months for their vaccines; your vet sets that schedule.
- Why do other cat age charts give slightly different numbers?
- There is no single official formula. The Cornell Feline Health Center, for example, puts a one-year-old cat at about 16 and a two-year-old at about 21, then adds about four a year. This calculator uses the International Cat Care and AAHA-endorsed chart, so treat the result as a close estimate, not an exact figure.