What's your dog's name?
We'll show you their real age using the latest science — and a few things you'll probably want to know about the years you share.
Used by dog lovers worldwide · Free · No sign-up
How old is your dog in human years?
If you've ever heard that one dog year equals seven human years, you've heard a myth. Dogs don't age at a linear rate, and they certainly don't age the same across breeds. A two-year-old Great Dane and a two-year-old Chihuahua are in entirely different life stages, despite being the same calendar age.
The calculator above uses the UCSD epigenetic aging formula — published in Cell Systems in 2020 — which tracks DNA methylation patterns to convert dog years into a biologically meaningful human age. Combined with breed-specific lifespan data from the American Kennel Club and peer-reviewed veterinary studies, you get the most accurate estimate available online, tailored to your dog.
Why the "× 7" rule is wrong
The multiply-by-seven rule assumed humans live about 70 years and dogs live about 10, so the math was simple. But it completely ignored two facts that veterinarians have known for decades:
- Dogs age fast at first, then slow down. A one-year-old dog is biologically closer to a 15-year-old human than a 7-year-old. After that, the pace settles.
- Size and breed matter enormously. Small breeds like Chihuahuas often live 16+ years. Giant breeds like Great Danes rarely pass 10. Every calculation needs to account for this.
Popular breeds
Curious about a specific breed? Each of these has its own aging calculator with breed-specific insights:
Want to go deeper?
We've written in-depth guides on everything from decoding life stages to caring for senior dogs: