Pet Age Calculator
Pets age faster than people, but not at a simple 7-to-1 rate. This calculator converts your dog or cat age into human years using a more realistic formula that takes your dog size into account, so you can understand what life stage your pet is really at.
Pet Age Calculator
How pet age converts to human years
Pets do not age at a steady rate. The first two years bring the biggest jump — roughly 15 then 24 human years — after which each pet year adds fewer human years. For dogs the rate depends on size, with larger breeds ageing faster than small ones.
Good to know
These figures are guidelines based on common veterinary estimates. Breed, health and lifestyle all affect how your individual pet ages.
Frequently asked questions
How old is my dog in human years?
A dog reaches about 15 human years in its first year and 24 by its second, then adds roughly 4-6 years per year depending on its size, with larger dogs ageing faster.
How old is my cat in human years?
A cat is about 15 human years after its first year and 24 after its second, then adds about 4 human years for each additional year.
Is the 7 dog years per year rule true?
No. The 7-to-1 rule is a myth. Pets age quickly when young and more slowly later, and dog ageing also depends on breed size.
Why do bigger dogs age faster?
Larger breeds mature and grow older more quickly and tend to have shorter lifespans than small breeds, which the size-aware formula reflects.
When is a pet considered senior?
Cats and small dogs are usually seniors from around 10-11 years, while large dogs can be seniors from about 7-8 years.