In this equation Dp is the density of population N is the total population as a number of people and A is the land area covered by that. The basic formula is. Density D Mass M Volume V so DMV.
The formula for calculating population density is Dp NA.
Density is a measure of relative compactness or how heavy an object is relative to its size. Typical unit is gmol. Here again you have two of the values and you can solve for the third by rearranging your formula to solve for mass. Equivalently it is its mass per unit volumes.