Density is defined as the mass of the substance divided by the volume.  The usual units in chemistry are grams (g) for mass and milliliters (mL) for volume.  The formula is therefore:


Where  ρ is the density, (greek letter "rho"*)

m = mass usually in grams

V = volume usually in mL

*  ρ is the standard SI symbol for density and not D or d.