Dog Age Calculator
Convert your dog's age into human years. This uses a size-adjusted model — small dogs and giant breeds age very differently — instead of the old ×7 rule.
Human-equivalent
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Check it outWhy size matters
Dogs grow up fast then diverge: a dog reaches about 15 human years by age one and ~24 by age two, after which small breeds age ~4 human years annually while giant breeds age ~7. That's why a 10-year-old Great Dane is “older” than a 10-year-old Chihuahua.
How it’s calculated
Year 1 ≈ 15 human years; year 2 ≈ +9 (24 total); then +4 to +7 human years per year depending on size.
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Worked example
A 3-year-old medium dog is about 29 human years (15 at year one, 24 at year two, then +5/year).
Common mistakes
- Using the old times-seven rule, which is inaccurate.
- Ignoring breed size, which strongly affects aging.
Where it is used
- Understanding a dog's life stage and care needs.
- Comparing aging across small and large breeds.
Frequently asked questions
Is the times-seven rule accurate?
No. Dogs mature much faster early on and then age at a rate that depends heavily on size and breed.
Why do big dogs age faster?
Larger breeds tend to have shorter lifespans, so each calendar year maps to more human years later in life.
Is this exact?
It's a well-supported estimate. Individual health, breed, and care all affect true aging.
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