Dog Age Calculator
Your dog's age in human years, adjusted for size, because small dogs age slower.
How dog years actually work
The old 'multiply by 7' rule is wrong at both ends. Dogs mature extremely fast at first: the first year corresponds to about 15 human years and the second to 9 more. After that, each dog year adds roughly 4 human years for small breeds up to 7 for giants, because large dogs age faster and live shorter lives, a Great Dane is elderly at 7 while a Chihuahua is middle-aged.
The DNA formula
A 2019 UC San Diego study compared DNA methylation clocks in labradors and humans and got human age ≈ 16 × ln(dog age) + 31. It agrees the first years count heavily (a 1-year-old dog is 'about 31') but flattens hard later. It's shown here as a second opinion; it was derived from a single breed.