Tool
Dog age calculator
Your dog’s age in human years, by size — two published methods side by side.
How this works
The old “multiply by seven” rule doesn’t hold up. Dogs mature fast in their first two years, and larger dogs age faster afterwards. We show two published approaches:
- AVMA size chart. The first year counts as about 15 human years and the second as about 9 more. After that, the American Veterinary Medical Association’s chart adds 4 years per dog year for small dogs and more for bigger dogs. The AVMA gives fixed points at 7, 10, 15 and 20 years; we draw straight lines between them. Its chart gives a single range for medium and large dogs, so those two sizes are spaced evenly between small and very large.
- DNA-methylation clock. A 2020 study of Labrador retrievers compared age-related DNA changes in dogs and people and proposed human age ≈ 16 × ln(dog age) + 31. It applies to dogs over one year and was built on one breed, so treat it as a curiosity.
Either way, most dogs count as seniors somewhere between about 7 and 10 years — earlier for giant breeds. Twice-yearly vet checks are commonly advised from then on.