Dog age calculator
How old is your dog in human years? Enter their age and size. It’s not seven years per year, and big dogs age faster than small ones.
How dog years work
The “multiply by seven” rule is a myth. Dogs race through childhood: by their first birthday most are the equivalent of a 15-year-old, and by two, about 24. From then on, each year adds roughly 4 to 9 human years, and the bigger the dog, the more each year counts.
The calculator uses the size-based chart below, which follows the American Veterinary Medical Association’s rule of thumb (15 years for the first year, about 9 for the second, then 4 to 5 for most dogs). It also shows the 2020 DNA-ageing estimate for comparison.
Dog years to human years chart
| Dog age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 1 | 15 | 15 | 15 | 12 |
| 2 | 24 | 24 | 24 | 22 |
| 3 | 28 | 28 | 28 | 31 |
| 5 | 36 | 36 | 36 | 45 |
| 7 | 44 | 47 | 50 | 56 |
| 10 | 56 | 60 | 66 | 79 |
| 12 | 64 | 69 | 77 | 93 |
| 14 | 72 | 78 | 88 | 107 |
| 16 | 80 | 87 | 99 | 121 |
Small: up to 9 kg (20 lb). Medium: 10 to 23 kg (21 to 50 lb). Large: 23 to 45 kg (51 to 100 lb). Giant: over 45 kg (100 lb). Read more in our guide to dog years to human years and caring for a senior dog.
PetTrackr helps you keep track. It is not veterinary advice: if your pet seems unwell, call your vet.
Questions people ask
Is one dog year really seven human years?
Why do big dogs age faster?
When is a dog a senior?
What is the DNA formula for dog years?
Care that changes as your dog does.
PetTrackr adjusts walk goals, weight ranges, check-up reminders and tips to your dog’s age and life stage. Join the waitlist for early access and a launch discount.