How to Calculate Dog Years
For decades people multiplied a dog’s age by seven to get “human years.” It’s simple — and wrong. A one-year-old dog is closer to a teenager than a seven-year-old child, and a Great Dane ages very differently from a Chihuahua.
The size-based method (AVMA)
The American Veterinary Medical Association uses a size-based table: for the first five years all dogs track similarly, then larger dogs pull ahead. A 10-year-old small dog is about 56 human years; a giant breed the same age is closer to 79. Our dog age calculator uses this table and lets you pick your dog’s size.
The science method (UCSD 2020)
A 2020 UC San Diego study of DNA methylation produced a formula — human_age = 16 × ln(dog_age) + 31 — that better reflects biological aging, especially in the early years. It estimates a one-year-old dog at about 31 human years. You can toggle this method in the calculator.
See the full chart
Want the year-by-year breakdown by size? See the dog years to human years chart, or jump straight to understanding your dog’s life stage.
Veelgestelde vragen
- Is 1 dog year 7 human years?
- No. The ×7 rule is a myth. Dogs mature much faster in their first two years, then aging slows — and larger breeds age faster than small ones.
- What is the most accurate dog age formula?
- For most owners the AVMA size-based table is the practical standard. The 2020 UC San Diego epigenetic formula (16·ln(age)+31) is the science-backed alternative.