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

A dog's first year is about 15 human years and the second adds about 9 (≈24). After that each dog year adds roughly 4–7 human years depending on size — small dogs age slower than giant breeds.

Is 1 dog year really 7 human years?

No. The ×7 rule is a myth. Dogs mature quickly early on and then age at a size-dependent rate, which the AKC size-based chart captures.

Dog Age Calculator — Dog Years to Human Years (by Size)

Breed Pet’s age: 2 years

24 human years

Adult Typical lifespan: 11–14 years

Size-aware estimate based on the AKC dog-age chart & veterinary life-stage guidance. A guide, not a diagnosis.

Dog age chart (by size)

The same number of birthdays means different things for a toy breed and a giant breed. Here’s the human-year equivalent for each size:

Dog age	Small	Medium	Large	Giant
1 year	15	15	15	15
2 years	24	24	24	24
3 years	28	29	30	31
5 years	36	39	41	45
7 years	44	49	52	59
10 years	56	64	68	80
13 years	68	79	85	101
16 years	80	94	101	122

Based on the AKC dog-age chart and veterinary life-stage guidance.

Dog life stages

Puppy — rapid growth; vaccines, socialization, training.
Young / adult — peak energy and health; establish routines.
Mature — watch weight and dental health; annual vet checks.
Senior — more frequent check-ups, joint support, and diet tuned for aging.

For general education only — not veterinary advice. Ask your vet about your dog’s individual health.

Dog years to human years

Dog age chart (by size)

Dog life stages