The density of population is an expression of the ratio between population and a given unit of size, It may be assessed in various ways and using various techniques:
(1) Crude Density or Arithmetic Density is the most common method. It is a straight measurement of the total number of people per unit of land.
i. Useful measure of population-resource relationship.
ii. It can not be treated as a measure of population pressure on land because it spells out a simple quantitative relationship between man and land.
(2) Nutritional /Physiological Density is the number of persons per unit of area of cultivated land.
i. It is a refined method of calculating man-land ratio.
ii. This gives a rather better indication of the standard of living.
(3) Agricultural Density is a density of agricultural population over cultivated area. It is a useful index of man-land relationship in primarily an agrarian context.
(4) Economic Density The ratio between the requirements of population and the resources made available to it by population in the areas it occupies.
(5) Room density is most commonly used in urban studies. It is the average number of people per room in a given area