Dog & Cat Age Calculator (in Human Years)
Convert your dog or cat's age into human years, adjusted for your dog's size.
Enter your pet's age to see it in human years.
Frequently Asked Questions
How do dog years convert to human years?
Pets age fast early on, then slow down. We count the first year as about 15 human years, the second as 9 more (24 total), and each year after that as 4, 5, or 6 human years for small, medium, and large dogs respectively — larger dogs age faster.
Why does my dog's size matter?
Small breeds tend to live longer and age more slowly in their later years, while large breeds age faster. Selecting your dog's size gives a more realistic human-age estimate after the second year.
How is a cat's age calculated?
Cats follow a single curve regardless of size: about 15 human years for the first year, 9 more for the second (24 total), then roughly 4 human years for each additional year.
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