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How old is a 4-year-old dog in human years?

A 4-year-old dog is about 32–38 in human years, depending on size: 32 for small, medium and large dogs and 38 for giant dogs.

Size

Not sure? We use medium.

How old is your pet?

At 4 years, a dog is

32 human years

Vet chart (by size)

Mature adult

No breed or size picked, so we assumed a medium-sized dog.

Other methods: DNA formula (UCSD study): 53 · The ×7 rule: 28

The default is the size-based vet chart. See how pet age is calculated.

Dog ages around 4

Dog age in human years, ages 1–7. Small is 20 lb or less, Medium is 21–50 lb, Large is 51–100 lb, Giant is over 100 lb.
Dog ageSmallMediumLargeGiant
1 year15151512
2 years24242422
3 years28282831
4 years32323238
5 years36363645
6 years40424549
7 years44475056

The default is the size-based vet chart. See how pet age is calculated.

4-year-old dog by breed

FAQ

How old is a 4-year-old dog in human years?

A 4-year-old dog is about 32–38 in human years, depending on size: 32 for small, medium and large dogs and 38 for giant dogs.

Is a 4-year-old dog old?

It depends on size. At 4, 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 4-year-old dog with the ×7 rule?

28, compared with 32 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.