Dog Age Calculator

Why "times 7" is wrong

A 1-year-old dog can reproduce and has adult teeth — that's not a 7-year-old human. The 2019 UC San Diego study compared DNA methylation clocks in Labradors and humans and found dog aging is logarithmic: human age ≈ 16 × ln(dog age) + 31. A 1-year-old dog is like a 31-year-old human; a 4-year-old like 53; after that, each dog year adds only a few human years.

Frequently asked questions

Why does size matter?

Unusually among mammals, bigger dogs age faster: a great dane is senior at 6, a chihuahua at 10. The size table reflects vet guidance — first year ≈ 15 human years, second ≈ 9, then 4–7.5 per year depending on size.

Which estimate should I trust?

The DNA formula is the best science but comes from one breed (Labradors); the size table encodes practical vet experience across breeds. Use them as a range — and your vet's assessment of joints, teeth and heart beats both.

When is a dog "senior"?

Roughly the last quarter of expected lifespan: 6–7 for giant breeds, 8–9 for large, 10+ for small dogs. Senior status mostly means twice-yearly vet checks and watching weight and joints.