Dog Years to Human Years Calculator

Convert your dog's age to human years instantly — using The Royal Kennel Club's size-adjusted guidance or the classic x7 rule.

225+
RKC breeds
4 sizes
weight bands
Free
no signup needed
36 human years
(30 years, 2 months)
6 dog years · German Shepherd Dog
Size-adjusted method
Simple ×7 rule would say: 21 human years

Entering the senior years

This is roughly when vets start recommending twice-yearly check-ups and when pet insurance premiums are worth reviewing.

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How this is calculated

The breed lookup maps each Royal Kennel Club-recognised breed to its official size band (Small, Medium, Large or Giant). The size-adjusted method then follows The Royal Kennel Club's own guidance: the first two years of a dog's life are roughly 24 human years for small, medium and large breeds (around 15 for year one, then 9 more), or about 22 for giant breeds. After that, each further dog year adds roughly 4 more human years for small breeds, rising to around 7 for giant breeds — reflecting that larger breeds mature and age faster. The older "1 dog year = 7 human years" rule is a 1950s rule of thumb that doesn't hold up scientifically, but is included here for comparison. Figures are estimates — individual dogs vary with genetics, health and lifestyle. Not a substitute for veterinary advice.
Pick a date to calculate their exact age.
Pick from 225+ Royal Kennel Club-recognised breeds.
Crossbreed or not listed? Switch to "Size category" and choose by your dog's adult weight instead.
Size-adjusted method Accounts for size — more accurate

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Frequently asked questions

What are dog years?

A dog's age in years is simply how long it has been alive — the same as it would be for a human. "Human years" is the equivalent age you get once that real age is translated using ageing guidance such as The Royal Kennel Club's, because dogs mature and age at a different pace to humans, especially early in life.

How do you convert dog years to human years?

According to The Royal Kennel Club, the first two years of a small, medium or large dog's life are roughly 24 human years (about 15 for year one, then 9 more), while giant breeds reach around 22 human years by age two. After that, each additional dog year adds a size-dependent number of human years — roughly 4 for small breeds, rising to around 7 for giant breeds. The older "1 dog year = 7 human years" rule is simpler but far less accurate.

Is the dog years x7 rule real?

No — the x7 rule is a 1950s rule of thumb, not based on science. Dog ageing isn't linear: a dog reaches near-adult size and the human equivalent of a teenager within its first year alone, then ageing slows considerably.

How many human years is 1 dog year?

It depends on the dog's age and size. In the first year alone, most dogs reach the human-equivalent of about 15 years old (around 12 for giant breeds). After that, ageing continues at a size-dependent pace of roughly 4 to 7 additional human years per dog year, according to The Royal Kennel Club.

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