Dog Age Calculator
Convert your dog's age to human years using modern veterinary formulas based on breed size.
Human-Equivalent Age
Dog age in human years is not a simple “multiply by 7” calculation. Modern veterinary science shows that dogs age faster in their early years, and size plays a major role.
Modern formula by size:
- Small dogs (<20 lbs): First year = 15 human years, second year = 9, each year after = 4
- Medium dogs (20–50 lbs): First year = 15 human years, second year = 9, each year after = 5
- Large dogs (>50 lbs): First year = 15 human years, second year = 9, each year after = 6
Why size matters:
- Small breeds tend to live 12–16 years and age more slowly after maturity
- Medium breeds tend to live 10–13 years
- Large/giant breeds tend to live 8–10 years and age faster in later years
Key milestones:
- All dogs reach roughly adult maturity at age 2 (~24 human years)
- A 5-year-old small dog ≈ 36 human years
- A 5-year-old large dog ≈ 42 human years