Dog Age Calculator (Dog Years)
Dog Age Calculator estimates your dog's age in human years using modern veterinary research. Enter your dog's age and size category to get the equivalent human age. Small breeds tend to live longer and age more slowly than large breeds.
Last updated: July 2026
A dog age calculator converts your dog's age to human years using the updated veterinary formula: the first year equals ~15 human years, the second year adds ~9, and each year after adds ~4–5 depending on breed size. Small breeds age slower than large breeds. All calculations run in your browser.
How to use Dog Age Calculator (Dog Years)
- Enter your dog's age in years.
- Select your dog's size/breed category (Small, Medium, Large or Giant).
- Read the equivalent human age and life stage.
Frequently asked questions
How accurate is the formula?
It's based on the updated veterinary consensus that dogs age faster in early years and the rate varies by breed size. It's a good estimate, not an exact science.
Why does breed size matter?
Small breeds (under 10 kg) tend to live longer and age slower after maturity. Giant breeds age fastest and have shorter lifespans.
Is my data stored?
No — the calculation runs entirely in your browser.
Related calculators
Cat Age Calculator (Cat Years)
Convert your cat's age to human years. Free, instant, in-browser — works for kittens and senior cats.
Age Calculator
Calculate exact age in years, months and days from any date of birth — plus total months, weeks and days. Free and instant.
BMI Calculator
Calculate your Body Mass Index (BMI) in metric or imperial units and see your weight category instantly. Free and private.
Percentage Calculator
Calculate percentages three ways: X% of a number, what % one number is of another, and percentage increase or decrease. Free and instant.