A 3-year-old dog is about
28–32
in human years, depending on size
Settled, fit, and at their peak. Regular exercise and yearly vet checks keep them there.
A 3-year-old dog is about 28 to 32 in human years. A small dog comes out at 28 and a giant dog at 32. If you're not sure which size your dog counts as, medium (21 to 50 lb or 10 to 23 kg) is a fair middle guide, at 28.
Bigger dogs age faster after the first two years, which is why the numbers spread out as dogs get older. The life stage shown above is for a medium dog.
Dog size
A 3-year-old dog is about 28 to 32 in human years. A small dog comes out at 28 and a giant dog at 32.
Generally, yes. Larger dogs tend to age faster and have shorter lives, which is why the chart gives bigger dogs a higher human age at the same calendar age.
Go by adult weight: small is up to 20 lb (9 kg), medium is 21 to 50 lb (10 to 23 kg), large is 51 to 90 lb (23 to 41 kg), and giant is over 90 lb (41 kg).
See the full dog years to human years chart, or compare with a 3-year-old cat.