🐕 Dog Age Calculator
Convert your dog's age into human years by accounting for different growth rates by size.
How to Use This Calculator
Enter your dog’s age
Provide the age in years (decimals allowed for months).
Choose the size category
Select small, medium, or large to apply the correct growth curve.
Review the result
Compare the calculated human age and notes about size-based aging.
Formula Overview
Small dogs (< 20 lbs): 12.5 human years per dog year for the first two years, then ~4.5 each year.
Medium dogs (20–50 lbs): 10.5 human years per dog year for the first two years, then ~5 each year.
Large dogs (> 50 lbs): 9 human years per dog year for the first two years, then ~6 each year.
Frequently Asked Questions
Why do aging rates vary by size?
Larger breeds grow rapidly during puppyhood and experience accelerated aging later in life. Smaller dogs tend to mature more slowly and often live longer.
Does this replace a veterinarian’s advice?
No. Use this calculator as a general guide. For precise health assessments, discuss your dog’s age and condition with a veterinarian.
Can I enter puppy ages?
Yes. Enter ages under two years to see the accelerated conversion. The calculator handles fractional values for months.
How can I extend my dog’s healthy years?
Focus on regular veterinary checkups, weight management, age-appropriate exercise, and preventive dental care.