See ANSI/A208.2 (2002), Standard for Medium Density Fiberboard. Depending on species and binders (interior or exterior glues), typical weights are 39 to 48 . This equates to 2.4 - 3 LB/Ft2 for 3/4" MDF.
Plain MDF density ranging from 690 kg/m3 to 790 kg/m3. High density flooring MDF has a density of 850 kg/m3
