How do you convert dog years to human years?

The first year of a medium dog's life equals about 15 human years. The second year equals about 9 more. Each subsequent year equals roughly 4–5 human years, depending on breed size.

Are small dogs and large dogs the same age in human years?

No. Large dogs age faster and have shorter lifespans. Our calculator adjusts the conversion based on your dog's size.

How old is a 10 year old cat in human years?

A 10-year-old cat is approximately 56 human years old, using the standard feline age conversion (first year = 15, second = 9, then +4 per year).

What is the oldest a dog has ever lived?

The oldest verified dog was Bobi, a Rafeiro do Alentejo from Portugal who lived to 30 years and 266 days, equivalent to over 200 human years.

Pet Age Calculator

How old is your pet in human years?

Dogs, cats, rabbits, hamsters, and horses — each species ages differently. Get the accurate human equivalent.

Pet Type

Dog Size

Pet's Date of Birth

How Pet Age Conversion Works

🐕

Dogs

The AKC-based formula considers breed size. Small dogs age slower in later years; large dogs age faster.

🐈

Cats

First year = 15 human years, second = 9, then 4 per year after. Indoor cats live 12–18 years average.

🐇

Rabbits

Rabbits have a 9:1 ratio to human years. A 5-year-old rabbit is ~45 in human years.

🐹

Hamsters

Hamsters age very rapidly — 25 human years per hamster year. They typically live 2–3 years.

How Pet Age Conversion Really Works

The old myth that one dog year equals seven human years is completely inaccurate. Dogs and cats mature much faster in their early years. According to modern veterinary standards (such as the AKC formula), the first year of a dog's life equals about 15 human years. The second year adds about 9 more years. After that, breed size matters immensely—large breeds age much faster and have shorter average lifespans than small dogs. Cats have their own unique aging curve, while animals like rabbits, hamsters, and horses age differently entirely. Understanding your pet's true age helps you provide better, age-appropriate veterinary care.