Dog Age Calculator

Enter your dog's date of birth for its exact age in years, its human-equivalent age using the 2020 epigenetic-clock formula, and (with a size picked below) whether it's reached the senior window for dogs that size.

How the pieces work

Age in years uses a 365.25-day year to account for leap years. Human age uses 16 × ln(dog age) + 31 (Wang et al. 2020), a formula built from Labrador retrievers only — see thehuman-years calculatorfor its limits. Senior status applies AAHA's "last 25% of expected lifespan" rule to the size-category median lifespan from a 2024 study of 584,734 dogs — see thesenior-age calculatorfor why that's an estimate, not an official cutoff.

If your dog is in the senior window

Footing and step height are usually the first things worth adjusting for an aging dog — before diet changes or supplements. See thefloor traction calculatorif slippery floors are part of the picture.

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