Dog Age Calculator
A one-year-old dog is about 31 in human years — not 7. Dogs age fast when young, then slow down. The formula below comes from DNA-methylation research, not folklore.
In human years, your dog is about…
42
human years — for a 2-year-old dog.
human = 16 × ln(age) + 31
Dog age chart: dog years to human years
| Dog age | Human years |
|---|---|
| 1 year | 31 |
| 2 years | 42 |
| 3 years | 49 |
| 4 years | 53 |
| 5 years | 57 |
| 6 years | 60 |
| 7 years | 62 |
| 8 years | 64 |
| 9 years | 66 |
| 10 years | 68 |
| 11 years | 69 |
| 12 years | 71 |
| 13 years | 72 |
| 14 years | 73 |
| 15 years | 74 |
| 16 years | 75 |
| 17 years | 76 |
| 18 years | 77 |
| 19 years | 78 |
| 20 years | 79 |
How it works: human age ≈ 16 × ln(dog age) + 31. The curve was calibrated on 104 Labrador Retrievers whose DNA methylation was matched to human aging. It is most reliable for dogs aged one year and older.
The chart lists the first 20 years; the calculator above answers for any age up to 30.
People look this up both ways. To convert human years to dog years, read the table above in reverse — because a dog ages fast when young and slowly later, no single number like “multiply by 7” works in either direction.
How long do dogs live?
A life table answers this better than an average does. Teng et al. (2022) built one from 30,563 dog deaths recorded by UK vets and put life expectancy at birth at 11.23 years — 11.41 for females and 11.07 for males. These are British dogs; the study says nothing about dogs elsewhere, and we have not found an equivalent table built on American records.
Breed moves that number far more than sex does. The same study measured the Jack Russell Terrier at 12.72 years and the French Bulldog at 4.53 years — the longest and the shortest of the breeds it could analyse. The American Kennel Club publishes 10–12 years for the French Bulldog, and the gap is not an error in either: a breed standard describes what a breed should be, a life table counts when dogs actually died.
Common questions
How many dog years is one human year?
There isn’t one number, because dogs don’t age at a steady rate. Using the epigenetic clock published by Wang et al. (2020), a one-year-old dog is already about 31 in human years, while the step from 10 to 11 adds closer to 1.5. The first year counts for a great deal; every year after it counts for less.
How do dog years work?
Wang et al. compared DNA methylation — chemical marks that accumulate on DNA with age — in 104 Labrador retrievers against the same marks in humans. The match is logarithmic, not linear: human age ≈ 16 × ln(dog age) + 31. That is the formula this calculator uses.
Is the “multiply by seven” rule true?
No. It would make a one-year-old dog seven in human years; the methylation clock puts it near 31. At the other end it overshoots: a 15-year-old dog would be 105, where the formula gives 74. The rule of seven is a rounding of average lifespans, not a measurement of aging.
Why does the calculator start at one year?
The formula is logarithmic, so below one year it returns numbers with no meaning. Puppy development in the first months is better described by growth stage than by a human-age equivalent.
Does breed or size change the answer?
The study measured 104 Labrador retrievers, so this formula does not model breed differences. Larger breeds are generally shorter-lived, and this number will read young for a giant breed and old for a small one. We publish the formula the study actually supports rather than adjusting it by breed with no source.
How long do dogs live?
Teng et al. (2022) built a life table from 30,563 dog deaths recorded by UK vets: life expectancy at birth was 11.23 years — 11.41 for females, 11.07 for males. Breed matters far more than sex: the same study measured the Jack Russell Terrier at 12.72 years and the French Bulldog at 4.53. These are British dogs; we have not found an equivalent table built on American records. It is a different question from the age conversion above — one counts deaths, the other converts an age.
This estimate reflects biological aging in Labrador-derived data. Individual dogs age differently by breed and health; it does not replace veterinary advice.
Verified on . Based on Life tables of annual life expectancy and mortality for companion dogs in the United Kingdom (Teng et al., Scientific Reports (2022), 12:6415, VetCompass — 30,563 deaths) and Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome (Wang et al., Cell Systems, 2020, vol. 11, no. 2, p. 176–185.e6 (DNA methylation in 104 Labradors)). See the method.