This short article argues that formulae utilized by archeologists for deriving populations from the floor areas of dwellings are flawed. The formulae in question are that of Naroll (1962), Clarke (1971), and Cook (1972) and he argues that each of these is either incorrect or simply too narrow or too broad. The author then puts forth his own formula for multifamily dwellings which he tests against a dataset of nine New World ethnographic examples. Finally, the author concludes that this type of formula needs to change depending on the type of dwelling in question.