Dog Age Calculator
Enter your dog's age and size to see a research-based estimate of age in human years and the likely life stage.
What changes as dogs age
Older dogs often sleep more, move more stiffly and need dental, joint and weight care. Read senior dog care and senior dog behavior changes for what is normal and what deserves a vet visit.
Frequently asked questions
Is one dog year really seven human years?
No. That rule is a rough shortcut. Dogs mature quickly in the first two years and then age more slowly, and the pace differs by size and breed.
What formula does this use?
A 2020 study of DNA methylation changes in Labrador retrievers produced the equation human age = 16 × ln(dog age) + 31. It is a research estimate, not a medical measure.
Do large dogs age faster?
On average large and giant breeds have shorter lifespans and reach senior status earlier, which is why the life-stage line changes with size.
Can I rely on it for my vet?
No. Your vet judges health and life stage from an exam. Use the result as a fun, approximate guide.