Why the cat chart differs from the dog one
Like dogs, cats mature quickly in their first years and then slow down — but on the scale used by veterinary associations, a cat's first year of life already equals 15 human years.
The chart used
In the first year, 1 cat year = 15 human years. In the second year, add 9 more (totaling 24 at 2 years). From the third year on, add roughly 4 human years for each additional cat year.
| Cat age | Equivalent human age |
|---|---|
| 1 year | 15 years |
| 2 years | 24 years |
| 5 years | 36 years |
| 10 years | 56 years |
| 15 years | 76 years |
Frequently asked questions
Is this chart an exact scientific formula?
It's a widely adopted approximation from veterinary associations, based on developmental milestones (teething, sexual maturity, general aging), not an equation derived from an epigenetic study like the dog one.
Do purebred cats age differently?
There can be some variation, but much less than between dog breeds (which vary far more in size). The chart works as a good general estimate.
Why is a cat's first year "worth" so much?
Because cats reach physical and reproductive maturity very quickly — at 1 year old they're already considered young adults, equivalent to a 15-year-old human.