Dog Age Calculator
Dogs do not age "7 years for every 1". The first year equals about 15 human years, the second adds 9 more, and after that the pace depends on size. Enter age and size to see the real number.
A chart-based approximation following established veterinary schedules. Individual aging depends on breed, weight and health.
The chart we use
year 1 = 15 human years · year 2 = 24 · then: small +4, medium +5, large +6 per year The schedule follows established veterinary age charts (AVMA and similar guidance on aging by breed size): rapid maturing in the first two years, then steady aging by size. The popular logarithm formula was calibrated only on Labradors, so we do not use it. Sources: Methodology.
Entering a new life stage?
When the stage changes (puppy, adult, senior), the portions change too. Get the new daily amount with the dog food calculator →
Frequently asked questions
Is the "1 dog year = 7 human years" rule true?
No. Dogs mature very fast early on: the first year equals about 15 human years and the second adds another 9. After that, each year adds 4 to 6 human years depending on the dog's size. The "times 7" rule underestimates young dogs and overestimates old ones.
Why does my dog's size matter?
Large breeds age faster after maturity: a Great Dane at 8 is deep into the senior years, while a Chihuahua at 8 is middle-aged. That is why the chart adds 4 human years per year for small dogs, 5 for medium and 6 for large.
When does my dog become a senior?
As a rule of thumb: small breeds around 10 to 11 years, medium breeds around 8 to 9, large breeds around 6 to 7. Seniors benefit from a checkup every 6 months instead of once a year.
What about the logarithm formula that made headlines?
The formula 16 x ln(age) + 31 comes from an epigenetic study done only on Labrador Retrievers, so we do not apply it to every breed. The size-based chart is the accepted veterinary reference for an arbitrary dog.