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How old is a 5-year-old dog in human years?

A 5-year-old dog is about 36–45 in human years, depending on size: 36 for small, medium and large dogs and 45 for giant dogs.

Size

Not sure? We use medium.

How old is your pet?

At 5 years, a dog is

36 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): 57 · The ×7 rule: 35

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

Dog ages around 5

Dog age in human years, ages 2–8. Small is 20 lb or less, Medium is 21–50 lb, Large is 51–100 lb, Giant is over 100 lb.
Dog ageSmallMediumLargeGiant
2 years24242422
3 years28282831
4 years32323238
5 years36363645
6 years40424549
7 years44475056
8 years48515564

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

5-year-old dog by breed

FAQ

How old is a 5-year-old dog in human years?

A 5-year-old dog is about 36–45 in human years, depending on size: 36 for small, medium and large dogs and 45 for giant dogs.

Is a 5-year-old dog old?

It depends on size. At 5, 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 5-year-old dog with the ×7 rule?

35, compared with 36 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.