How far a pound of powder goes and how much you need for a part, from the powder's specific gravity and the film thickness you're after.
192.3 is the area one pound of material with the density of water covers at 1 mil thick. Powders are denser than water, which is what specific gravity measures, so heavier powders cover less. This is the theoretical figure. In practice some powder never reaches the part, which the utilization percentage accounts for.