About your dog
About your dog
Result
Dog’s age in human years
Enter your dog’s age or date of birth and choose their adult size.
Dog’s age in human years
–human years
Dog’s age–
Dog size–
Next birthday–
Your dog’s age journey
Compare their current age, next birthday and estimated start of the senior stage
–
–human years
How is a dog’s age calculated?
The first years of a dog’s life do not equal the later years
01
First year
A one-year-old dog is roughly comparable to a 15-year-old person because dogs mature very quickly.
02
Second year
At two years old, a dog is approximately equivalent to a 24-year-old person.
03
Size matters
After maturity, small dogs generally age more slowly than large and giant dogs.
04
Individual differences
Breed, genetics, body condition, diet and health can all affect how an individual dog ages.
Dog age in human years: chart
Approximate equivalents by adult dog 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 | 42 | 45 |
| 7 years | 44 | 49 | 54 | 59 |
| 10 years | 56 | 64 | 72 | 80 |
| 15 years | 76 | 89 | 102 | 115 |
Frequently asked questions
Practical answers about dog years, size and life stages
No. Dogs mature especially quickly during their first two years, and later ageing also varies with adult size and breed.
The first year is estimated at about 15 human years and the second at 24. From the third year, this calculator adds a size-dependent amount.
Large breeds generally have a shorter average lifespan and may show age-related changes earlier. Choose the dog’s expected healthy adult weight.
There is no single age for every dog. This calculator uses an approximate threshold of 10 years for small, 9 for medium, 7 for large and 6 for giant dogs.
Choose “I know the age” and enter an estimated number of years and months. A vet may also estimate age from teeth, eyes, coat and body condition.
It is a general guide, not a biological measurement. Individual dogs and breeds can age differently.
Dog years and human years are not the same
A dog age calculator offers a simple way to compare your pet’s age with a human life stage. Life stage can also help you think about exercise, preventive checks and everyday care.
The familiar “multiply by seven” rule ignores a puppy’s rapid early development. A one-year-old dog is already physically comparable to a teenager, while a two-year-old is closer to a young adult.
This calculator uses a simplified size-based model: about 15 human years for the first dog year, 24 by the second, then a faster annual increase for larger dogs. The result is an estimate, not a diagnosis.
American Kennel Club: calculating dog years · AAHA: canine life stages