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Dog Age Calculator

Dog Age Calculator works out Human-equivalent age and Age used from Age in years, Extra months and Date of birth. The default figures on this page give human-equivalent age of 39.0 years; change any entry and the result, the working and the sources update together.

Human-equivalent age
39.0 years
Dog and Cat Age Calculator
Age used
5.000 years
Age in months
60.0 months
Life stage of the human-equivalent age
Young adult
Human years gained per pet year now
5.00 years
Reaches human-equivalent 65 at
10.20 years
Model used
AVMA / AAHA staged canine model, size-adjusted
Size band used
Medium (21-50 lb / 9-23 kg)
Age taken from
age entered directly
Summary
A 5-year-old dog is about 39 in human years (young adult).
Worked out from American Veterinary Medical Association, "How old is my pet in human years?" guideline as published in the AKC dog-age conversion chart and 2 other sources.
Age conversion is a rough population guide, not a health assessment. Life stage, senior screening and any change in care should be decided by a veterinarian who has examined the animal.

Your figures

Updates as you type
Leave the birth date blank to use this. Fractions are fine - 0.5 is six months.
If given, the age is measured from this date and the years/months boxes are ignored.
The date the age is measured on. Leave blank to use the current date supplied by the page.
Larger breeds age faster after maturity. Ignored for cats.

How this is worked out

6 steps
  1. Age used: 5 dog years (age entered directly).
  2. First two years = 15 + 9 = 24 human years.
  3. Each year after the second is worth 5 human years for medium (21-50 lb / 9-23 kg): 5 x 3 = 15.
  4. Total = 24 + 15 = 39 human years.
  5. At this age the animal gains about 5 human years per pet year.
  6. Human-equivalent 65 is reached at about 10.2 dog years.
Age conversion charttable
petYearshumanYears
115
224
329
434
539
644
749
854
959
1064
1169
1274
1379
1484
1589
1694

Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed

Sources and references

3 sources
American Veterinary Medical Association, "How old is my pet in human years?" guideline as published in the AKC dog-age conversion chart
First year of a medium dog ≈ 15 human years, second year ≈ 9 more, each later year ≈ 4 (toy/small), 5 (medium), 6 (large) or 7 (giant) human years.
International Cat Care / AAFP / AAHA feline life-stage age conversion
First cat year ≈ 15 human years, second ≈ 9 more (24 by age two), and about 4 human years for every year after that.
Wang T, Ma J, Hogan AN, et al. Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome. Cell Systems 11(2):176-185 (2020)
2020 · Epigenetic clock fitted to 104 Labrador retrievers and 320 humans: human_age = 16 * ln(dog_age) + 31.

What the Dog Age Calculator calculates

Converts a dog or cat’s age into human-equivalent years using the AVMA/AAHA staged model by size, or the Wang (2020) canine epigenetic clock, and reports the life stage that age falls into.

How to use this Dog Age Calculator

Enter Age in years, Extra months, Date of birth and Age as of. Human-equivalent age updates as you type. Change one figure at a time to see what drives the result.

How the result is worked out

Open “How this is worked out” beside the result for the step-by-step calculation behind Human-equivalent age, Age used and Age in months.

The method follows American Veterinary Medical Association, "How old is my pet in human years?" guideline as published in the AKC dog-age conversion chart, International Cat Care / AAFP / AAHA feline life-stage age conversion and Wang T, Ma J, Hogan AN, et al. Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome. Cell Systems 11(2):176-185 (2020).

What you can compare

Change one input at a time to see how it affects Human-equivalent age, Age used and Age in months. The inputs you can vary are Age in years, Extra months, Date of birth, Age as of, Adult size (dogs) and Conversion model.

Understanding Human-equivalent age, Age used and Age in months

Age conversion is a rough population guide, not a health assessment. Life stage, senior screening and any change in care should be decided by a veterinarian who has examined the animal.

Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.

Embed this calculator on your website

Copy this code into any page. The calculator appears with the figures currently entered, sizes itself to fit, and a small credit line links back here. Free, no account, no ads inside it, no tracking of your readers. Set your own figures and fixed fields; Personal removes the credit line, sets your colour and shows you which sites use it.

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Frequently asked questions

How do I figure out my dog's age in dog years?

Converts a dog or cat’s age into human-equivalent years using the AVMA/AAHA staged model by size, or the Wang (2020) canine epigenetic clock, and reports the life stage that age falls into. Open “How this is worked out” beside the result to see each step for your own figures.

Is 7 dog years 1 human year?

Converts a dog or cat’s age into human-equivalent years using the AVMA/AAHA staged model by size, or the Wang (2020) canine epigenetic clock, and reports the life stage that age falls into. On the figures this page opens with — age in years 7 — the human-equivalent age is 39 years. Put your own figures in their place and the working updates beside the result.

How old is a 14-year-old dog in dog life?

It needs Age in years, Extra months, Date of birth, Age as of, Adult size (dogs) and Conversion model. Nothing else is required, and the figures stay in your browser.

How old is a 7 year old dog?

The result gives Human-equivalent age, Age used, Age in months, Life stage of the human-equivalent age, Human years gained per pet year now and Reaches human-equivalent 65 at, each labelled with its unit so the figure can be read on its own.

What information do I need for the Dog Age Calculator?

You need Age in years, Extra months, Date of birth, Age as of, Adult size (dogs) and Conversion model. The page opens with default figures that give human-equivalent age of 39.0 years, so you can see the scale before entering your own.

What does this Dog Age Calculator show?

It shows Human-equivalent age, Age used, Age in months, Life stage of the human-equivalent age, Human years gained per pet year now, Reaches human-equivalent 65 at, Model used and Size band used, with the working and any warnings for your entries.

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