Tools
How old is your dog, really?
Enter an age and a full-grown size. Three published methods answer at once, and one of them is the myth.
Work out the answer
Enter the age in weeks, months or years — whichever you actually know. The range starts at eight weeks, which is where the first stage opens, and runs to eighteen years.
e.g. Beagle, Boston Terrier — about 22 to 55 lb full-grown. Adult size changes the life stage and the senior threshold, not the human-age comparisons. None of the three published methods here adjusts its arithmetic for size: the AVMA staged estimate is written around a medium dog, the epigenetic clock was fitted to one breed and carries no size term, and the seven-times rule ignores size entirely — which is one of the reasons it is wrong.
There is no single human age for a dog. Each figure below is one published method's approximation, named with the method that produced it, and they disagree by design — the gap between them is the honest answer.
The AVMA staged estimate
Approximate human-age comparison
29
15 for the first year, 9 for the second, about 5 a year after.
A rough estimate for a medium dog. It does not stretch or shrink for a Chihuahua or a Great Dane.
The UCSD epigenetic clock
Approximate human-age comparison
48.6
16 x the natural log of the dog's age, plus 31.
The study sequenced 104 Labrador Retrievers. Breeds age differently, and both the AKC and UC Davis note that a single-breed study may lack enough variables for conclusive results. Treat the curve as insight, not as your dog's chart.
The seven-year rule (myth)
Approximate human-age comparison
21
Multiply by seven. We show it because you will recognise it.
Debunked. It underestimates a young dog badly and overestimates an old small dog. Shown for recognition only.
WagYears stage (our editorial framing)
Adult · 2 to 8 years
Useful gear for the adult stage
These are the picks the stage page itself resolves, so you can see what this stage needs without opening another page first. Nothing is bought from this page.
- Slow Feeders & BowlsPETLIBRO Granary 5L Wi-Fi Automatic Feeder$89.99
- Dental CareWHIMZEES Dental Chews$37.31
Or compare the whole shelf: Slow Feeders & Bowls · Dental Care · Orthopedic Beds
The six stages are ours. AAHA's clinical framework names five stages — puppy, young adult, mature adult, senior and end of life — defines them by development rather than by birthdays, publishes no inclusive ages for mature adult or senior, and deliberately declines to give human-year equivalents. Our windows are a routing device for finding the right page, not a clinical line, and adolescent is not an AAHA stage at all.
Why the three methods disagree
- The AVMA staged estimate
- The UCSD epigenetic clock
- The seven-year rule — dashed, and a myth
Each line is one published method's approximate human-age comparison, drawn from the same functions that produce the numbers above. They agree least where it matters most — the first two years — and the dashed line is the 7x rule, plotted only so the size of the error is visible. The shaded marker is where the AVMA's senior guidance begins for the size you selected; it is a threshold in the dog's own years, not in the converted ones.
Read the chart as a table
| Dog age | The AVMA staged estimate | The UCSD epigenetic clock | The seven-year rule |
|---|---|---|---|
| 1 | 15 | 31 | 7 |
| 2 | 24 | 42.1 | 14 |
| 3 | 29 | 48.6 | 21 |
| 4 | 34 | 53.2 | 28 |
| 5 | 39 | 56.8 | 35 |
| 6 | 44 | 59.7 | 42 |
| 7 | 49 | 62.1 | 49 |
| 8 | 54 | 64.3 | 56 |
| 9 | 59 | 66.2 | 63 |
| 10 | 64 | 67.8 | 70 |
| 11 | 69 | 69.4 | 77 |
| 12 | 74 | 70.8 | 84 |
| 13 | 79 | 72 | 91 |
| 14 | 84 | 73.2 | 98 |
| 15 | 89 | 74.3 | 105 |
| 16 | 94 | 75.4 | 112 |
The AVMA staged estimate is scaled linearly inside each of its published bands — our arithmetic on their figures, not part of the published guideline. The epigenetic clock comes from one breed and says nothing about a dog under a year. The 7× rule is shown only so you can see how far off it is. Approximate. AAHA gives no fixed ages: it defines life stages by development, not by birthdays, and publishes no inclusive ages at all for mature adult or senior. These windows are ours, built so you can find the right page. A dog a month either side of a line is the same dog.
When the AVMA calls a dog a senior
- Small or toy breeds (less than 20 pounds)8 to 11 years
- Medium-sized breeds (20 to 50 pounds)8 to 10 years
- Large breeds (50 to 90 pounds)8 to 9 years
- Giant breeds (more than 90 pounds)6 to 7 years
Older restatements of AVMA guidance (still on the AKC and UC Davis pages) put small dogs at about seven and larger breeds at five to six. The AVMA's current page uses the weight bands above.
Nothing you type here leaves your browser. There is no account, no email box and no saved result — close the tab and it is gone.
A worked example: a seven-year-old Labrador
- The AVMA staged estimate puts a dog of this age at about 49 in human terms. It is written around a medium dog and does not adjust for a Labrador being a large one — no published method here does.
- The epigenetic clock, which was built from a single breed and carries no size adjustment at all, reads about 62.1 instead. Two published methods, a real gap between them, and no way to call one of them wrong.
- The seven-times rule would say 49. It is on the page only so you can see how far off it is: it has no research behind it, and UC Davis traces it to nothing more than two average lifespans.
- The number that actually changes what you do is the stage. This dog is in the Adult stage, 2.5 to 8 years for a large dog, which is where screening bloodwork, weight and the household's floors start to matter more than anything on the human-years line.
- Change the adult size to toy and the three human-age figures do not move at all, while the stage window does. That is the whole job of the size control: a big dog reaches the senior threshold years before a small one.
Or skip the arithmetic: open the adult stage and read what changes, or browse the picks by need and stage.
Where these numbers come from
- AVMA, quoted in AKC, How to Calculate Dog Years to Human Years — 15 human years equals the first year of a medium-sized dog's life. Year two for a dog equals about nine years for a human. And after that, each human year would be approximately five years for a dog.
- Wang et al., Cell Systems (2020) — PubMed 32619550 — 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.e6 (2020). The abstract states the cohort: 104 Labrador retrievers spanning a 16 year age range.
- UC Davis Veterinary Medicine, Calculating Your Dog's Age — Plain-language explainer of the study and its milestone alignment table.
- AAHA 2019 Canine Life Stage Guidelines — definitions — AAHA defines five canine life stages by development rather than by fixed ages, defines senior as the last 25 percent of estimated lifespan, publishes no inclusive ages for mature adult or senior, and does not use human-year equivalents.
- AVMA, Senior Pets (opened 2026-09-07) — Dogs don't have a universal age of seniority because of their wider variety in size. Larger breed dogs tend to have shorter life spans than smaller breeds. For this and other reasons, experts suggest that dogs be considered senior when they reach the last 25 percent of the estimated life span for their breed.
- Salt C, Morris PJ, German AJ, et al. Growth standard charts for monitoring bodyweight in dogs of different sizes. PLoS ONE (2017), Table 1 — Toy under 5 kg, small 5 to under 10 kg, medium 10 to under 25 kg, large 25 to 40 kg, giant over 40 kg.
Partial years inside a band are scaled linearly. That smoothing is our arithmetic, not part of the published guideline, which is why it is said here rather than presented as a published figure.
How old is my dog in human years, age by age
Every age on one page, deliberately. Each answer gives the AVMA staged estimate and the UCSD epigenetic figure, and says where size changes the meaning. If the two numbers disagree, that disagreement is the useful part: it tells you how much of this is estimate.
- How old is a 1-year-old dog in human years?
- About 15 on the AVMA's staged guideline, which treats a dog's first year as worth fifteen human ones. The UCSD epigenetic clock puts it much higher, at about 31, because the molecular work says a young dog has already done most of a human adolescence. Both agree the first year is the fastest. In stage terms a one-year-old is usually adolescent, whatever the number says.
- How old is a 2-year-old dog in human years?
- About 24 by the AVMA guideline: fifteen for the first year, then roughly nine more for the second. The epigenetic clock gives about 42. The gap between those two numbers is the widest it ever gets, and it is why we print both. Most two-year-olds are finishing adolescence and settling into adult, though a giant breed may still be in it.
- How old is a 3-year-old dog in human years?
- About 29 by the AVMA guideline, which adds roughly five human years for each year after the second. The epigenetic clock says about 49. Three is where AAHA expects most dogs to have completed physical and social maturation, so whichever number you prefer, the honest answer is that this is a fully adult dog.
- How old is a 4-year-old dog in human years?
- About 34 by the AVMA guideline and about 53 by the epigenetic clock. Size starts mattering here in a way the formulas cannot see: a four-year-old giant breed is two years from the senior threshold the AVMA currently puts at six to seven for dogs over 90 pounds, while a four-year-old toy breed has years of adult life ahead.
- How old is a 5-year-old dog in human years?
- About 39 by the AVMA guideline, about 57 by the epigenetic clock. Five is where size starts to fork. The AVMA currently puts giant breeds over 90 pounds at senior around six to seven, so a five-year-old Great Dane is a year or so out, while a five-year-old Chihuahua is squarely middle-aged. Ask your vet where your dog sits, because the answer changes what a check-up should include.
- How old is a 6-year-old dog in human years?
- About 44 by the AVMA guideline and about 60 by the epigenetic clock. Six is where the AVMA's senior window opens for giant breeds over 90 pounds. Dogs under 90 pounds are generally not considered senior until eight or later. If your dog is a giant breed, this is the year to ask your vet about baseline senior bloodwork.
- How old is a 7-year-old dog in human years?
- About 49 by the AVMA guideline, about 62 by the epigenetic clock. Seven is the number most people have heard, partly because older AVMA guidance put small dogs at senior around seven. The AVMA's current page puts senior at 6 to 7 for giant breeds and 8 or later for everyone else, so a seven-year-old Great Dane is a senior and a seven-year-old beagle is not yet. UC Davis reports the UCSD study aligning seven to twelve dog years with roughly seventy human ones.
- How old is an 8-year-old dog in human years?
- About 54 by the AVMA guideline and about 64 by the epigenetic clock. Eight is senior for essentially every size class. Practically, this is the age where twice-yearly check-ups start earning their cost, because six months is a long time in an older dog and most of what matters is caught by noticing a change rather than by a symptom.
- How old is a 9-year-old dog in human years?
- About 59 by the AVMA guideline, about 66 by the epigenetic clock. Notice that the two numbers have almost converged: the AVMA line keeps climbing at five a year while the epigenetic curve flattens. That flattening is the study's actual claim, that aging slows in later life. Nine is comfortably senior for any size of dog.
- How old is a 10-year-old dog in human years?
- About 64 by the AVMA guideline and about 68 by the epigenetic clock. For a giant breed, ten is a considerable age; for a small dog it is a comfortable one with years likely ahead. The AAHA definition of senior is the last quarter of expected lifespan, which is why the same number means such different things at different sizes.
- How old is an 11-year-old dog in human years?
- About 69 by the AVMA guideline and about 69 by the epigenetic clock. Eleven is the one age where the two methods agree almost exactly, which is a coincidence of the curves rather than a confirmation of either. Above eleven the AVMA figure climbs faster than the epigenetic one, and the gap reopens in the other direction.
- How old is a 12-year-old dog in human years?
- About 74 by the AVMA guideline, about 71 by the epigenetic clock. The methods have now crossed over. A twelve-year-old small dog is old and frequently still doing well; a twelve-year-old large dog has outlived the average for most big breeds. Mobility, dental comfort and cognition are the three things worth raising at every visit now.
- How old is a 13-year-old dog in human years?
- About 79 by the AVMA guideline and about 72 by the epigenetic clock. Thirteen is beyond the range of the UCSD study's oldest well-represented dogs, so treat the epigenetic figure as an extrapolation rather than a measurement. In practice this is deep in the senior stage, and what helps is traction, warmth, a supportive bed and shorter walks more often.
- How old is a 14-year-old dog in human years?
- About 84 by the AVMA guideline, about 73 by the epigenetic clock. Fourteen is a long life for most dogs and an unusual one for a large breed. Both formulas are now well past the point where a single number is useful. What the dog can do today, and how comfortable they are doing it, tells you more than any conversion.
- How old is a 15-year-old dog in human years?
- About 89 by the AVMA guideline and about 74 by the epigenetic clock. Fifteen is a remarkable age. AAHA names end of life as a formal stage of its own, and the useful conversation at this point is not arithmetic but quality of life: ask your vet what scale they use to assess it, and ask before you think you need to.
The number is a conversation starter. The stage is the thing that changes what you do, and it is what the calculator above shows underneath the years.
The questions behind the numbers
- Why is the 7-year rule wrong?
- Because dogs do not age at a constant rate. UC Davis traces the rule to nothing more than the average lifespans of dogs and humans, ten and seventy, and points out that dogs age far faster than humans in their first years. The AKC quotes Kansas State veterinarian William Fortney calling it a marketing ploy, a way to encourage owners to bring their pets in at least once a year. Multiplying by seven underestimates a young dog badly and overestimates an old small one.
- Why does a dog's size change how fast they age?
- Nobody fully knows, which is the honest answer. What is documented is the effect: the AKC reports evolutionary biologist Cornelia Kraus finding that every 4.4 pounds of body mass reduced a dog's life expectancy by about a month, with the mechanism still unexplained. Size also changes the start of life: veterinary growth research finds very small dogs mature at eight to twelve months while larger breeds can take up to twenty-four. Big dogs move through every stage faster.
- What does it mean when a dog is called a senior?
- Clinically, AAHA defines senior as the last 25 percent of a dog's estimated lifespan through end of life, which makes it a proportion rather than a birthday and means it arrives years earlier in a big dog. The working numbers the AVMA currently publishes, by weight, are 8 to 11 years under 20 pounds, 8 to 10 at 20 to 50 pounds, 8 to 9 at 50 to 90 pounds, and 6 to 7 over 90 pounds. Senior is not a diagnosis. It is the age at which it becomes worth looking for things.
- Is the UCSD epigenetic formula reliable?
- It is real research and it is narrow. The University of California San Diego study, published in Cell Systems in 2020, sequenced DNA methylation in 104 Labrador Retrievers across a sixteen-year age range and derived human age equals sixteen times the natural logarithm of dog age, plus thirty-one. Both the AKC and UC Davis attach the same caveat: the study used a single breed, breeds age differently, and the formula may lack enough variables for conclusive results. Read it as insight into the shape of aging, not as your dog's chart.
Do not know your dog's age at all? The care-path finder works from what you can see instead.