🐶 Dog Age to Human Years Calculator

Dogs mature quickly in the first years of life, then more slowly. This calculator uses a simple size‑based curve:

• The first year ≈ 15 human years for most dogs.
• The second year adds ≈ 9 human years.
• Each additional year adds 4–6 human years depending on size (smaller dogs age more slowly).

This is a common rule‑of‑thumb model; real aging varies by breed, genetics, health, and lifestyle. Your veterinarian can give you a more precise view of your dog’s life stage.