About this hub
Most pet-age sites split one question across a dozen thin pages and quietly use whichever formula ranks. We built the opposite: one hub where dog age (size-aware, with life stage), cat age and feeding calories sit together, every number labelled with the method behind it.
Sources, checked 30 Oct 2026
DNA methylation (epigenetic clock) study of 104 Labrador Retrievers compared with humans, reported by UC San Diego. It produced the formula human years = 16 × ln(dog age) + 31. The study used Labradors, so the formula does not account for size — which is why we show the size-based view alongside it.
AKC's published chart of human-year equivalents by dog age and size (based on AVMA guidance): ages 1–5 are 15, 24, 28, 32, 36 for every size, then the sizes diverge — for example age 10 is 56 (small), 60 (medium), 66 (large) and age 15 is 76, 83, 93. Our size-based numbers are looked up from exactly those published values for whole years (AKC publishes ages 1–16, checked 30 Oct 2026). Part-years are interpolated in a straight line between chart years, and ages 17–20 extend the chart's final yearly step (+4 small, +4 medium, +6 large) — those later ages are our extension, not AKC-published values, and we label them as such.
The cat chart behind our converter — year 1 ≈ 15 human years, year 2 ≈ 24, then +4 per year — is the life-stage chart published with the 2021 AAHA/AAFP Feline Life Stage Guidelines: kitten to 1 year, young adult 1-6, mature adult 7-10, senior over 10.
RER = 70 × (weight in kg)^0.75. MER factors used here: neutered adult dog 1.6, intact adult dog 1.8, puppy under 4 months 3.0, puppy 4 months+ 2.0, weight-loss dog 1.0; neutered adult cat 1.2, intact adult cat 1.4, kitten 2.5, weight-loss cat 0.8. Individual needs vary — vets adjust from body condition.
What is a convention, honestly labelled
The size-based dog chart and the cat chart are widely used veterinary conventions, not measurements — we say so wherever they appear. The UCSD formula is peer-reviewed science, but from one breed (Labradors), and we say that too. The feeding calculator's 360 kcal-per-cup starting value is a typical editable default, never a claim about any brand; the field exists so you can replace it with the figure printed on your own food. Grams assume roughly 100 g per cup of dry food — weigh your cup for precision.
Disclaimer
General guidance only, not veterinary advice. Age conversions are comparisons to help you plan care; calorie figures are starting points. Pets that are pregnant, lactating, ill, very young, or changing weight unexpectedly need a vet, not a calculator.