Dog Age Calculator
Convert your dog's age to human years by size — plus life stage and the newer DNA-based estimate.
Dog-to-human age conversions are estimates. Breed, weight and health all affect how a dog ages — ask your vet about your dog’s needs at each life stage.
About this tool
Enter your dog's age and size to see its age in human years using the veterinary rule of thumb, its life stage, and the epigenetic-clock estimate from recent DNA research. Smaller dogs age more slowly than large breeds after the first two years.
Frequently asked questions
No. Dogs mature very fast at first: a one-year-old dog is roughly like a 15-year-old human and a two-year-old like a 24-year-old. After that, each year adds about 4–7 human years depending on size.
Large and giant breeds have shorter average lifespans and reach their senior years sooner — often around 6–8 years old, compared with about 10 for small dogs.
A 2020 study measuring DNA methylation in Labrador retrievers proposed human age ≈ 16 × ln(dog age) + 31. It suggests dogs age especially fast when young. It was based on one breed, so treat it as an interesting estimate.
As a guide: small dogs around 10 years, medium around 9, large around 8 and giant breeds around 6. Your vet can advise when to start senior check-ups.
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