Pick your animal and convert pet years to human years — or flip it around and turn a human age into pet years.
This hub gives you a quick answer for any of these animals. For the full chart, life-stage guide, and more detail, visit the dedicated page for your pet:
Dogs use the American Kennel Club (AKC) size-based chart, because a small dog and a giant breed age very differently — so this tool asks for your dog's size. Cats use the standard veterinary formula (first year ≈ 15, second adds ≈ 9, then ≈ 4 a year). Horses start at about 6.5 human years for the first year and add about 2.5 a year once grown. Rabbits reach about 20 by age one, then add about 6 a year. Hamsters are estimated from development milestones because they age so fast — treat their numbers as rough.
Switch the direction to Human years → pet years and enter a human age to see how old that would be for your pet. The calculator works backward through the same chart for whichever animal you pick.
Dog figures follow the AKC size-based chart (via the Old Farmer's Almanac); cats use the standard veterinary formula; horse, rabbit, and hamster figures are stage-based estimates (hamster numbers are especially rough). These are general estimates for information, not veterinary advice.