Dog Age Calculator
See your dog's age in human years and their life stage by size. Bigger dogs age faster in later life, so size changes the math. Use it to make age-aware decisions about food, movement, and vet visits.
How the Dog Age Calculator Works
A dog's first year is roughly 15 human years. The second year adds about 9 more. After that, each year adds between 4 and 7 human years depending on size, because larger dogs age faster as they get older. This tool uses that size-adjusted approach rather than the old and inaccurate "multiply by seven" rule.
What to Do With Your Dog's Life Stage
Knowing your dog's stage helps you plan. Mature and senior dogs benefit from more frequent vet checks, joint-friendly movement, and closer attention to early cognitive changes, signs of pain, and sleep quality. For the full picture, start with our guide to helping an aging dog feel better.
This calculator gives an estimate for general guidance only. Your veterinarian is the best source for your dog's individual health and life stage.