Dog age calculator guide
This English page translates the Korean dog-age calculator and calls calculateHumanAge, classifyDogSize, determineLifeStage, calculateRemainingLifespan, and calculateLifeProgress. It keeps the AVMA-style 2026 size-based model instead of the old one dog year equals seven human years shortcut.
Size-based human-age conversion
The Korean calculator separates dogs by weight: small under 10 kg, medium 10 to 25 kg, large 25 to 45 kg, and giant 45 kg or more. Each size uses a different first-two-year factor and a different aging factor after year two.
Small dogs use 12.5 human years for each of the first two dog years and 4 human years after that. Medium dogs use 10.5 and 5, large dogs use 9 and 7, and giant dogs use 8 and 8. A 5-year-old small dog therefore lands near 37 human years, while a 5-year-old large dog lands near 39 human years.
Life stage and remaining lifespan
The Korean source does more than convert an age. It classifies the pet as puppy, junior, adult, mature, senior, or geriatric using size-specific thresholds, then estimates remaining lifespan from a size or breed lifespan range.
The English calculator keeps that structure. The life progress percentage is based on the average lifespan for the selected size, so it can show why a giant dog reaches senior-management timing earlier than a small dog with the same calendar age.
Care interpretation
Use the result to plan checkups, nutrition, weight control, dental care, exercise, and home environment. Mature and senior stages should normally trigger more frequent health checks and more attention to joint, heart, kidney, dental, and weight issues.
The output is a planning model, not a diagnosis. Actual lifespan varies by breed, genetics, neutering status, disease history, body condition, veterinary care, and living environment.