Pet

Dog Age in Human Years Calculator

Convert a dog's age to a rough human-equivalent age using the logarithmic ageing curve.

This result means the dog is at a life stage comparable to a person of about that age, as a rough guide only, not a veterinary assessment.

Formula

For dogs aged one and over, human-equivalent age is about 16 times the natural log of dog age, plus 31; puppies under one are scaled roughly linearly.

How it works

The logarithmic curve reflects that dogs age fast early and then more slowly. Breed size shifts real ageing a lot, so this is a population guide, not a breed-specific figure.

Worked example

For example, for a 5-year-old dog, 16 × ln(5) + 31 = 56.75, which the calculator rounds to about 57 human-equivalent years.

FAQs

Why not multiply by 7?
The old 7-times rule ignores that puppies age much faster than older dogs.

Do big dogs age faster?
Yes, large breeds tend to age faster than small breeds.

Is this a health check?
No. It is an age comparison only.

General information only, not veterinary advice.

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