The specific density of a product is very important when comes the time to compare product costs.
In order to compare the cost of a product to another’s, it is imperative to know its specific density and to transform the weight (kg) to volume (litre).
Thus, 25 kg of product A with a specific density of 1.25 gr/cubic cm has a volume of 20 litres.
That same 25 kg of product B, which has a specific density of 1.50 gr/cubic cm, equals a volume of 16.666 litres.
Therefore, for the same price, product A has a higher volume (20 litres) than product B (16.666 litres).
Using the price of those two products, it will then be possible to compare their cost per litre.
A price comparison should be by volume (litre) and not by weight (kg).