Dog age calculator
Convert your dog's age into human years using the size-based method, which reflects how dogs really age far better than the old multiply-by-7 rule.
In human years, your dog is about
24
human years old
How the dog age calculator works
Dogs do most of their growing up fast. By their first birthday a dog is roughly the equivalent of a 15-year-old human, and by their second they are closer to a 24-year-old. After that, aging slows down and becomes steadier, adding about 4 to 7 human years for every dog year.
The size of your dog matters because smaller breeds tend to live longer and age more slowly, while large and giant breeds age faster. That is why this tool asks for breed size: a small dog adds about 4 human years per year, a medium dog about 5, a large dog about 6, and a giant breed about 7. Pick the band that best matches your dog's adult weight for the closest estimate.
This is an estimate, not an exact science. Genetics, diet, exercise, and overall health all shape how a dog ages. If you want to keep your dog feeling young, two of the biggest levers you control are weight and nutrition. Use our dog calorie calculator to check daily feeding, and scan their food with Pawpoy to make sure the ingredients suit them.
Frequently asked questions
How do you calculate a dog's age in human years?
The first year of a dog's life is worth about 15 human years and the second adds roughly 9 more, bringing a 2-year-old dog to about 24. After that, each dog year adds 4 to 7 human years depending on size, since larger breeds age faster. This calculator uses that size-based method.
Is the old 'multiply by 7' rule accurate?
No. Multiplying by 7 is a rough shortcut that overstates the early years and understates the later ones. Dogs mature very quickly in their first two years, then age more steadily. The size-based method used here lines up much better with how dogs actually age.
Why does breed size change the result?
Small dogs tend to live longer and age more slowly, while giant breeds age faster and reach their senior years sooner. That is why a 10-year-old small dog and a 10-year-old giant breed land on very different human-year numbers.
When is a dog considered a senior?
Most small and medium dogs are considered senior around 8 to 10 years, while large and giant breeds reach that stage closer to 6 to 7 years. Senior pets benefit from more frequent vet checks and often a diet change, so it is worth knowing where your dog sits.
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Scan your first label freeThis calculator gives general guidance only, not veterinary advice. Always consult your veterinarian for medical decisions about your pet.