How do you calculate a dog's age in human years?

Dog aging varies by size. Small dogs age slower than large dogs. The first year equals about 15 human years, the second year adds 9 more, then 4-5 years for each additional dog year depending on breed size.

Is the 7-year rule for dog age accurate?

No, the multiply by 7 rule is a myth. Dogs mature much faster in their first two years and then aging slows down. Additionally, large breeds age faster than small breeds, so a more accurate calculation accounts for breed size.

What is the average lifespan of dogs by size?

Small dogs typically live 15-20 years, medium dogs 10-15 years, large dogs 8-12 years, and giant breeds 6-10 years. Smaller dogs generally live longer because they age more slowly than larger breeds.

Dog Age Calculator

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How Dog Age Works

The old "multiply by 7" rule is a myth. Dog aging varies by size:

Small dogs: Age slower, often live 15-20 years
Medium dogs: Average aging, live 10-15 years
Large dogs: Age faster, live 8-12 years
Giant breeds: Age fastest, live 6-10 years

Dog Life Stages

Puppy: Birth to 6-12 months (rapid growth)
Adolescent: 6-18 months (social development)
Adult: 1-7 years (depending on size)
Senior: Final third of expected lifespan

Did You Know?

A 1-year-old dog is roughly equivalent to a 30-year-old human in development.
The oldest verified dog lived 29 years and 5 months (Bluey, an Australian Cattle Dog).
Dogs' first year equals about 15 human years, second year adds 9, then 4-5 per year after.

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The Ugly Empire Team

Software engineers and data specialists with backgrounds in financial services, mathematics, and educational technology. Our team builds tools using industry-standard formulas verified against authoritative sources.

Last reviewed: January 2026

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Disclaimer: This calculator provides estimates for informational purposes only. Results should not be considered financial, legal, medical, or professional advice. Always consult qualified professionals for important decisions. We strive for accuracy but cannot guarantee results will match real-world outcomes due to varying factors and individual circumstances.

Dog Age Calculator

How Dog Age Works

Dog Life Stages

Did You Know?

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