Comparing your dog’s age with human years can be interesting, but it is always an approximation. Dogs develop rapidly when young, and their rate of ageing varies with size, breed and health. Multiplying every birthday by seven misses those differences.
What an age comparison can tell you
An age chart is a broad illustration of life stages. It cannot diagnose a health problem, measure an individual dog’s biological age or predict their lifespan. Smaller dogs often live longer than larger dogs, but there is considerable variation within each group.
For one consistent reference, our dog-age comparison table uses the American Veterinary Medical Association’s published figures for a medium-sized dog weighing 21–50 lb, approximately 9.5–23 kg. Examples include about 15 human years at age one, 24 at age two, 36 at age five and 60 at age ten. These figures should not be applied as exact equivalents to every breed.
Try the dog-age calculator
This optional tool is provided by World Animal Foundation. It uses its own estimates, so results may differ from the AVMA table or our older factsheet. Use the result as a conversation starter with your vet.
Open World Animal Foundation’s calculator in a new tab.
Download the dog-age factsheet
Download our dog-age factsheet (PDF). This 2024 factsheet uses simplified size-based rules of thumb: 15 at one year, 24 at two years, then approximately four, five or six human years per additional dog year. These are illustrative shortcuts, not the same model as the AVMA reference table above or a validated prediction for an individual dog.
Care for the dog in front of you
Life-stage care is more useful than a single human-age number. The American Animal Hospital Association describes a dog’s senior stage in relation to the later portion of their expected lifespan, rather than one birthday that applies to all breeds.
Ask your vet about an appropriate check-up schedule and changes to nutrition, activity and home comfort. Report changes in movement, appetite, drinking, sleep or behaviour rather than assuming they are simply part of getting older. Training and enrichment can continue with activities suited to your dog’s comfort and ability.
Sources: AVMA age-comparison chart and AAHA life-stage guidance.
Reviewed October 2026.
