Dog Age Calculator
How old is your dog in human years? Enter your dog's age and size for an accurate conversion.
How is dog age calculated?
The old "1 dog year = 7 human years" rule is a myth. Modern veterinary science uses a more accurate model: the first year equals ~15 human years (rapid development), the second year adds ~9 more (24 total), and each subsequent year adds ~4 human years. Large dogs age faster than small dogs, so we apply a size modifier to reflect this difference.
Frequently Asked Questions
My dog was born on a specific date β how old is she in human years?βΎ
First, calculate how old your dog is in dog years: subtract their birth year from the current year (adjust if their birthday hasn't occurred yet this year). Then enter that number above and select their size. For example, a dog born in September 2023 is about 1.5 years old β enter 1.5 and click Calculate.
How old is a 7-year-old dog in human years?βΎ
A 7-year-old medium dog is approximately 47 human years old. Small dogs age a little slower (around 40 human years) and large dogs faster (around 56 human years) at the same age.
How old is a 1-year-old dog in human years?βΎ
A 1-year-old dog is equivalent to about 15 human years β regardless of size. Dogs mature extremely rapidly in their first year, reaching near-adult size and sexual maturity.
Is '1 dog year = 7 human years' accurate?βΎ
No β it's a rough myth. The modern formula used by veterinarians is: year 1 = 15 human years, year 2 adds 9 more (24 total), and each year after adds about 4 human years. Large dogs also age faster than small dogs, which a flat 7Γ ratio ignores.
Do large dogs age faster than small dogs?βΎ
Yes. Large breeds (50+ lbs) tend to have shorter lifespans and age faster relative to smaller breeds. This calculator applies a size modifier: small dogs age slightly slower, large dogs slightly faster than the medium baseline.
How old is a puppy born this year in human years?βΎ
A puppy born earlier this year would be under 1 year old in dog years β but already 6β15 human years depending on how many months old they are. Enter their age as a decimal (e.g. 0.5 for a 6-month-old puppy) for the best estimate.