How do you calculate a dog's age in human years?

A dog's first year equals about 15 human years, the second year adds about 9 more (reaching ~24), and each year after that adds 4–7 human years depending on breed size. Smaller dogs age more slowly in later life than giant breeds.

Is the 'multiply by 7' rule accurate?

No. The old 'one dog year equals seven human years' rule is a myth. Dogs mature very fast in their first two years and then age at a rate that depends heavily on their size and breed.

Do small dogs live longer than large dogs?

Yes. Small breeds often live 14–16 years while giant breeds may only reach 7–10 years, so the same chronological age maps to a much older human age in a giant breed.

Dog Age Calculator

Convert your dog's age into human years — adjusted for breed size, using the latest veterinary chart.

Quick answer A dog's first year is about 15 human years, and the second year adds roughly 9 more — so a 2-year-old dog is about 24 in human years. After that, each year adds 4–7 human years depending on breed size (about 4 for small breeds, up to 7.5 for giant breeds). For example, a 7-year-old dog is roughly 44 (small breed) to 62 (giant breed) in human years.

Your dog's age

Breed size — based on adult weight

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human years

How the dog age calculator works

Forget the old "multiply by 7" rule — it's a myth. Dogs grow up fast and then age at a pace set largely by their breed size. PawWise uses the size-adjusted chart adopted by the American Animal Hospital Association (AAHA):

Year 1 ≈ 15 human years (puppies mature very quickly)
Year 2 adds ~9 years (a 2-year-old dog ≈ 24 in human terms)
Each year after adds 4–7 human years, depending on size

Dog years to human years chart

Dog age	Small	Medium	Large	Giant
1 yr	15	15	15	15
2 yr	24	24	24	24
3 yr	28	29	30	32
5 yr	36	39	42	47
7 yr	44	49	54	62
10 yr	56	64	72	84
13 yr	68	79	90	107
16 yr	80	94	108	129

Why size changes the answer

Small breeds like Chihuahuas often live 14–16 years, while giant breeds like Great Danes may only reach 7–10. So a 7-year-old small dog is roughly middle-aged (about 44), but a 7-year-old giant breed is already a senior (about 56). Knowing your dog's true life stage helps you adjust diet, exercise, and how often you schedule vet checkups.

⚠️ This calculator is an estimate for general guidance and isn't a substitute for veterinary advice. Individual dogs age differently based on genetics, weight, and health.

Frequently asked questions

Is the "1 dog year = 7 human years" rule true?

No. It's a long-standing myth. Dogs reach the equivalent of human adolescence within their first year and adulthood by age two, then age more gradually at a rate tied to their breed size.

At what age is a dog considered a senior?

Small dogs are usually seniors around 10–11 years, medium around 8–10, large around 8, and giant breeds as early as 6–7 years.

How long do dogs live on average?

Roughly 10–13 years overall, but small breeds frequently reach 15+ while giant breeds average closer to 8.

Next: check how much to feed your dog or use our cat age calculator.