Not listed or a mixed breed? Tap a dog above to choose the size.
An estimate is fine. For a puppy under one year, choose 0 years.
How the calculation works
Dogs grow up fast. The first year counts as about 15 human years and the second adds about 9 more, which makes a two-year-old dog roughly 24. After that, each calendar year adds a different amount depending on the dog's size.
| Size | Adult weight | Human years per dog year after age 2 |
|---|---|---|
| Small | under 10 kg (22 lb) | 4 |
| Medium | 10 to 25 kg (22 to 55 lb) | 5 |
| Large | 25 to 45 kg (55 to 100 lb) | 6 |
| Giant | over 45 kg (100 lb) | 7 |
Frequently asked questions
How do I calculate my dog's age in human years?
The first year of a dog's life counts as about 15 human years and the second year adds about 9 more. After that, each dog year adds 4 human years for small breeds, 5 for medium, 6 for large and 7 for giant breeds.
Why does breed size matter?
Larger dogs tend to age faster and have shorter lifespans than smaller dogs, so a giant breed reaches old age sooner than a small one of the same calendar age.
Is the old rule of 7 dog years per human year correct?
No. The one-to-seven rule is a rough myth. Dogs mature quickly in their first two years and then age at a rate that depends on their size.
What if my dog is a mixed breed?
Choose the size that best matches your dog's adult weight: small under 10 kg (22 lb), medium 10 to 25 kg (22 to 55 lb), large 25 to 45 kg (55 to 100 lb) and giant over 45 kg (100 lb).
Can I enter the birth date in either format?
Yes. Choose DD/MM/YYYY or MM/DD/YYYY, then type the date in that order.
Terms and conditions: This calculator gives a rough estimate for general interest only. Dogs age differently depending on genetics, health and lifestyle, and no formula is exact. The results are not veterinary advice and should not be used to make health or care decisions. Please speak to a qualified veterinarian about your dog's health. Everything is provided as is, without warranty of any kind, and everytoolhub.tools accepts no liability for decisions made using this tool.