How old is a 3-year-old dog in human years?
A 3-year-old dog is about 28–31 in human years, depending on size: 28 for small, medium and large dogs and 31 for giant dogs.
At 3 years, a dog is
28 human years
Vet chart (by size)
No breed or size picked, so we assumed a medium-sized dog.
Other methods: DNA formula (UCSD study): 49 · The ×7 rule: 21
The default is the size-based vet chart. See how pet age is calculated.
Dog ages around 3
| Dog age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 1 year | 15 | 15 | 15 | 12 |
| 2 years | 24 | 24 | 24 | 22 |
| 3 years | 28 | 28 | 28 | 31 |
| 4 years | 32 | 32 | 32 | 38 |
| 5 years | 36 | 36 | 36 | 45 |
| 6 years | 40 | 42 | 45 | 49 |
The default is the size-based vet chart. See how pet age is calculated.
3-year-old dog by breed
FAQ
How old is a 3-year-old dog in human years?
A 3-year-old dog is about 28–31 in human years, depending on size: 28 for small, medium and large dogs and 31 for giant dogs.
Is a 3-year-old dog old?
It depends on size. At 3, dogs of every size are mature adults. Vets consider a dog a senior in the last quarter of its expected lifespan.
How old is a 3-year-old dog with the ×7 rule?
21, compared with 28 on the vet chart for a medium dog. The ×7 rule is a myth: pets age fast in their first two years and more slowly after that.