Based on UC San Diego DNA methylation research. Not "times seven."
Visual comparison of dog years vs human years across life stages.
Most dog age calculators use a simple linear multiplier (times 7, times 5, etc.). That is wrong. Dogs do not age linearly. Here is what we actually do:
Rapid growth multiplier based on developmental milestones. A 3-month-old puppy has the coordination of a toddler. A 6-month-old is like a pre-teen. This phase is compressed childhood.
Logarithmic curve from the UC San Diego DNA methylation study. Dogs age fastest in human-year terms during this period. A dog goes from ~20 human years at 6 months to ~42 at age 2.
Size-adjusted linear model. Small dogs add ~4 human years per calendar year. Giants add ~6. Breed-specific lifespan modifiers applied (e.g., brachycephalic breeds age faster).