Is this an exact conversion?

No — it's a widely used approximation based on general aging patterns. Individual dogs vary by breed, health, and genetics, so treat this as a general guide, not a veterinary assessment.

Why do larger dogs age faster in human years?

Larger dog breeds tend to have shorter overall lifespans and experience more rapid physical aging in their later years compared to small and medium breeds.

Dog Age Calculator

Convert your dog's age into human years using a size-adjusted approximation — not the old (and inaccurate) "multiply by 7" rule.

Dog's age

years

Size

Human Age Equivalent

36 years

How It Works

Why 'multiply by 7' is wrong

Dogs mature much faster than humans early in life and slow down later — a 1-year-old dog is closer to a 15-year-old human, not a 7-year-old.

A size-adjusted formula

The first year counts as about 15 human years, the second year adds about 9 more (24 total), and each year after that adds roughly 4-5 human years depending on the dog's size — larger dogs age faster in their later years.

Example Calculation

A 5-year-old small-to-medium dog is roughly 36 in human years, while a 5-year-old large dog is roughly 39, since larger breeds age faster after their second year.

Common Mistakes

Using the outdated 'multiply by 7' rule, which significantly overstates the age of young dogs and understates older dogs.
Ignoring breed size — larger dogs tend to have shorter lifespans and age faster in human-year terms than small breeds.

Frequently Asked Questions

Is this an exact conversion?: No — it's a widely used approximation based on general aging patterns. Individual dogs vary by breed, health, and genetics, so treat this as a general guide, not a veterinary assessment.
Why do larger dogs age faster in human years?: Larger dog breeds tend to have shorter overall lifespans and experience more rapid physical aging in their later years compared to small and medium breeds.