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Dog Age Calculator

Translate your dog's age into human years with modern DNA-based and traditional methods — adjusted for breed size.

Human-equivalent age
39 human years
Traditional (size-adjusted)39 years
Modern (Wang et al., 2020)56.8 years

Two Methods, One Truth

The modern method (Wang 2020) uses DNA methylation data. The traditional method counts the first year as 15, second as 9, and 5 per year after — adjusted for size. Both are shown.

Modern: human age = 16 × ln(dog age) + 31

Frequently Asked Questions

Is 1 dog year really 7 human years?

No — that old rule is a myth. Dogs age fast early in life (a 1-year-old dog is like a 15-year-old human) then slow down. Size also matters hugely.

What's the Wang 2020 formula?

A 2020 UC San Diego study used DNA methylation patterns: human age ≈ 16 × ln(dog age) + 31. More accurate than the old 7× rule.

Why does size affect dog aging?

Large breeds age faster than small ones. A Great Dane at 7 is roughly equivalent to a human in their 60s, while a Chihuahua at 7 is more like mid-40s.

What's the oldest dog age?

Most dogs live 10–13 years. Small breeds often reach 15+. The verified record is 29 years (an Australian Cattle Dog named Bluey).

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