4 years in dog years is about 32 human years

4 years in human years, by size

Dog age calculator, with 4 years filled in: change the size, or work a human age back to dog years.

A mature adult

For AAHA a dog is a mature adult from the end of maturation, 3 to 4 years in most dogs, until the last 25% of its expected life. The guidelines suggest an exam every six months to a year at this stage, with an annual minimum database: the baseline tests a veterinarian compares later results with.

Merck’s table lists 4 dog years as 32 human years, the same as AVMA’s chart for a medium dog. The DNA clock, at about 53, is more than 20 years older here, the widest gap between the clock and the medium chart.

What changes from 3 to 4

This birthday adds 4 for a small dog, 4 for a medium dog, 5.5 for a large dog and 7.5 for a giant dog in human years on the chart. The DNA clock adds 4.6.

Life stage at 4

Dogs of every size are mature adults at 4, by the stages of the 2019 AAHA guidelines and the senior ages of VCA (small 11, medium 10, large 8, giant 7).

No size turns senior at exactly 4.

What the DNA clock says about a 4-year-old dog

Wang et al. (Cell Systems, 2020) matched the DNA methylation of 104 Labrador retrievers with that of people and fitted human age = 16 × ln(dog age) + 31. For 4 years that is 53.2 human years, 21.2 more than the 32 of AVMA’s chart for a medium dog.

At 4, the clock reads older than the chart of every size: it ages young dogs much faster than the charts do.

The seven-year rule at this age

Seven times 4 is 28. The chart puts a 4-year-old dog between 32 and 39 human years by size, and the medium dog at 32, so the rule is 4 human years too low for a medium dog. No veterinary source on this page uses it.

Frequently asked questions

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

About 32 for a small dog (20 lb or less), 32 for a medium dog (21 to 50 lb), 35 for a large dog (51 to 100 lb) and 39 for a giant dog (over 100 lb), on the charts of AVMA, Merck and PetMD. Your veterinarian can tell you where your own dog is.

Is a 4-year-old dog a senior?

Not by size alone: VCA counts dogs as seniors from 7 (giant) to 11 or 12 (small), so a 4-year-old of any size is not there yet. AAHA defines a senior as a dog in the last 25% of its expected life.