The density Index (Id) for warse grained soils

ID = $\frac{emax-e}{emax-emin}$

Id=$\frac{1/\gamma dmin-1/\gamma d}{1/\gamma dmin-1/\gamma dmax }$

Where,

emax= maximum void ratio (loosest state)

emin=minimum void ratio (denset state)

e= Natural void ratio of soil

$\gamma dmax$= maximum Dry density

$\gamma dmin$=minimum Dry density

$\gamma d$=Dry Density in natural state

The density Index varies from 0 to 100%