Dog age calculator: your dog's age in human years

The old "multiply by seven" rule doesn't hold: dogs grow up far faster than that in their first two years, then age more steadily. The American Veterinary Medical Association publishes a chart for a medium-sized dog, and the calculator above reads from it.

Dog years to human years: the AVMA chart

The AVMA bases the chart on a medium-sized dog weighing 21–50 lb (about 10–23 kg) and calls the figures approximate. Weight, breed and health all affect how a dog ages.

Size changes the picture

Bigger dogs age faster in their later years. The AKC says small dogs are generally considered senior at about 7, while larger breeds are often senior at about 5 to 6, and it cites research finding that every 4.4 lb (2 kg) of body mass cut a dog's life expectancy by about a month. So read the chart as a middle value: a small dog is often a little younger in human terms than the table says, a giant breed a little older.

Why it matters

Knowing your dog's "human" age is a reminder that change comes quickly. A dog that turns eight has aged about as much in a year as a person does in four or five. That is when sleep patterns, appetite and energy start to shift, and when a regular log helps you notice the change early; our guides on senior dog sleep changes and why a dog sleeps a lot cover what is normal.