Tell us about your dog
Reverse mode: find the dog age that each method maps to a given human age.
Used only in your browser to compute upcoming birthdays and stage transitions.
Results — three methods, side-by-side
Life stage
Aging curves
Human-equivalent age vs dog age for the selected size. Shaded bands are the six life stages (AVMA scale). The dot marks your dog.
Try an example
How the three methods work
1. AVMA rule of thumb (size-adjusted)
The American Veterinary Medical Association guideline (via the AKC): the first year of a medium-sized dog’s life equals 15 human years, the second year adds about 9, and each year after that adds approximately 5. We extend it with size-adjusted rates used across veterinary charts: small +4, medium +5, large +6, giant +7 per year after year two. It is a rule of thumb, not exact science.
2. AKC chart (FetchFind 2020)
A published weight-based chart (0–20 lb / 21–50 lb / 51–90 lb / over 90 lb) featured with the AKC dog-age calculator. Integer table anchors are interpolated linearly for fractional ages; beyond the published table the curve extends with the table’s own tail slope.
3. Wang 2020 epigenetic clock
human_age = 16 × ln(dog_age) + 31 — from Wang et al., Cell Systems 2020 (UC San Diego). The team compared DNA-methylation aging markers in 104 Labrador Retrievers against humans. It is the most science-grounded of the three, but it was built from a single breed, so it is size-blind and least certain for very young puppies.
All three are models of population averages. Individual dogs vary enormously by genetics, weight, neuter status, and care.
More dog tools
- Dog Life Expectancy Calculator — how long is your dog likely to live? (age conversion vs lifespan: different questions)
- Dog BMI Checker — is your dog’s weight healthy for its breed?
- Puppy Weight Calculator — how big will your puppy get?
- Pet Food Calculator — how much should you feed per day?
Frequently asked questions
What is the “16 × ln(dog age) + 31” formula?
It is the epigenetic dog clock from Wang et al. (Cell Systems, 2020): researchers at UC San Diego compared DNA-methylation aging markers in 104 Labrador Retrievers against humans and found human_age = 16 × ln(dog_age) + 31. A 1-year-old dog scores 31 human years, a 4-year-old 53.2, and a 7-year-old 62.1. Limitation: it was built from a single breed, so treat it as a model, not a diagnosis.
Why do the three methods on this page give different answers?
They model different things. The AVMA rule of thumb is a vet guideline (year 1 = 15, year 2 = +9, then a size-based rate). The AKC chart is a published weight-based table. The Wang 2020 clock is a DNA-methylation model from one Labrador study. For a 5-year-old medium dog: AVMA says 39, the AKC chart says 38, and Wang says 56.8. The agreement panel shows the range and the consensus (median) so you see the uncertainty instead of a false single number.
Why do small dogs age more slowly than large dogs?
Large dogs grow faster and their bodies wear out sooner — every ~4.4 lb of extra body mass is linked to about a month less life expectancy (Kraus, University of Göttingen). The size effect shows up in the numbers: a 10-year-old small dog converts to 56 human years (AVMA), while a 10-year-old giant dog converts to 80. Note the Wang 2020 clock is size-blind (built from Labradors only), which is one reason the methods can disagree for very small or giant breeds.
Is the “multiply by 7” rule accurate?
No — it is a myth. Dogs age fastest in their first two years: a 1-year-old dog is already a young adult in human terms (31 by the epigenetic clock, 15 by the AVMA rule), not 7. The 7:1 ratio likely came from the rough statistic that people lived to ~70 and dogs to ~10. Every method on this page — AVMA, AKC chart, and Wang 2020 — rejects the flat multiplier.
When is my dog considered a senior?
It depends on size. Our six life stages are calibrated to the AVMA's own senior guidance (small dogs senior ~7, large breeds 5–6): a small dog becomes senior at about 7.3 years, a medium dog at 6.2, a large dog at 5.5, and a giant breed at 5. The senior vet-screening planner above adjusts check-up frequency to the stage.
How is this different from a dog life expectancy calculator?
Different questions. This tool converts age: “how old is my dog in human years right now?” A life expectancy calculator answers “how many years is my dog likely to live in total?” If you want the lifespan question — breed and size-based longevity estimates — use our dog life expectancy calculator. Use this page for the age-conversion question.
Does this calculator predict my puppy's adult weight?
No. Age conversion and weight prediction are different jobs. For an estimate of how big your puppy will get, use our puppy weight calculator, which uses growth-curve data by size class. This page only converts between dog years and human-equivalent years.
Can this tell me when my pregnant dog will give birth?
No — age conversion has nothing to do with pregnancy timing. For a due-date estimate from a mating or ovulation date, use our dog pregnancy calculator. This page only converts ages between dog years and human years.
How does reverse mode (human years → dog years) work?
Each method inverts exactly. For example, 30 human years converts to 3.2 dog years (AVMA, medium), 3.2 (AKC chart, medium), but only 0.94 (Wang 2020) — the epigenetic clock runs much faster early in life, so the same human age maps to a younger dog. The AVMA and AKC inverses are piecewise-exact; the Wang inverse is dog = e^((human − 31)/16).
Is this veterinary advice?
No. This is an educational tool built from published guidelines and studies (AVMA, AKC, Wang et al. 2020). It does not diagnose, treat, or predict any individual dog's health or lifespan — breed lines, weight, neuter status, and care matter enormously. For health decisions, talk to your veterinarian. If you are tracking nutrition too, our pet food calculator and dog BMI checker can help.