Density is the ratio of … quantity of something / area that delineates something... for example
the Number of people/ square kilometer
Percentage is the ratio of …
something/total number of somethings …. for example
children in the room/total number of people * 100
density and percentage can only be related when you are talking about the... the number of areas off something relative to the total area of all somethings....
… the number of houses / town area (this is density) ...… versus.... total area of all houses / town area (this is percentage/ratio)
so what are you working with?
Consider 1 house on a building lot... the area of the building lot is 1 acre (43560 ft^2) the house is 1000 ft^2
The density is 1/43560.... the percentage is 1000/43560
two different things