Dog Age Calculator
Enter your dog's age and size to see their age in human years, using both the modern DNA-based formula and the classic size chart, plus their current life stage.
Two methods, two numbers - the truth is somewhere in between. The "multiply by 7" rule is far too rough.
How dog years are estimated
We show two accepted methods:
Epigenetic (2020): human = 16 x ln(dog years) + 31 (from age 1)
Classic: year 1 = 15, year 2 = +9 (24), then +4 to +7 per year by size
Larger breeds age faster after the first two years, which is why size matters. Life stage (puppy, adult, senior) follows common veterinary thresholds.
Source: Wang et al., Cell Systems (2020); AKC size-based chart.
Frequently asked questions
Is 1 dog year really 7 human years?
No, that rule of thumb is far too rough. Dogs mature fast early on (year one is about 15 human years), then age more slowly, and larger breeds age faster than small ones.
Why does this show two numbers?
The epigenetic clock is based on 2020 DNA research and fits the first years well; the classic size-adjusted chart is a familiar rule of thumb. Different sources vary, so we show both.
When is a dog a senior?
Roughly: small breeds around 11 years, medium 10, large 8 and giant breeds 7. Larger dogs reach senior status sooner.
Does breed size really matter?
Yes. After the first two years, larger dogs age faster in human-year terms, which is why we ask for a size class.