Question 1

Is one dog year equal to seven human years?

Accepted Answer

No. The 7× rule is folklore. Wang et al. (Cell Systems, 2020) map dog chronological age to human-equivalent age with human_age = 16 × ln(dog_age) + 31.

Question 2

Where do the size-chart ages come from?

Accepted Answer

The size-class human-equivalent table values are from the AAHA physiological-age poster, adapted from Dog Owner’s Home Veterinary Handbook (Eldredge et al.).

Dog age calculator