The Density of a substance is its mass per unit volume. It is also known as the volumetric mass density. The symbol most often used for density is ρ (the lower case Greek letter rho), although the Latin letter D can also be used.  The density of a material varies with temperature and pressure. This variation is typically small for solids and liquids but much greater for gases.  Increasing the temperature of a substance (with a few exceptions) decreases its density by increasing its volume.

Mean density, or more precisely, the mean volumetric mass density, of a substance is the average mass per unit volume of a substance in its most common or naturally occurring state.  The vCalc symbol for mean density is `muD`.  The standard units for mean density are kilograms per cubic meter.  However, vCalc provides automatic conversions to other units via the pull-down menu including (lb/ft³) pound per cubic foot, (g/cm³) grams per cubic centimeter, (t/m³) metric tons per cubic meter, (ton/yd³): tons (U.S.) per cubic yard, (oz/in³) ounces per cubic inch.  For a quick lookup of mean density of substances click HERE.