Dog Age Calculator - How Old is My Dog in Human Years?
Estimate your dog’s age in human years based on age and size.
This is a general estimate. Breed, health, and individual development affect aging.
How dog years are calculated
The “multiply by seven” rule misses how quickly dogs mature. This calculator starts with the veterinary guideline of about 15 human years for the first dog year and 9 more for the second, then applies a simple size adjustment for later years. The result is an approximation, not a measure of biological age.
Sources: UC Davis School of Veterinary Medicine and the American Veterinary Medical Association’s senior-pet age chart.
Why dog size matters
UC Davis notes that small dogs tend to live longer than large dogs, and AVMA age comparisons give different human-age ranges by dog size. Breed, weight, health, and veterinary care also influence a dog’s life stage, so the calculator’s size adjustment remains a rough comparison.