Typical densities for commonly encountered dry soils. Ice rich soils can have substantially smaller dry densities.

Normally, dry densities are used in most calculations (g_d); however, the total density of a soil (including moisture) can be calculated as follows:

For example, if a gravel has γ_d = 130 lb/ft³ and w = 5%, then γ_t = 130(1 + 5/100) = 136.5 lb/ft³

Soil moisture content can be calculated as follows:

The thermal conductivity is the rate of heat flow through a unit area under a thermal gradient (recall that 1 BTU is the energy (heat) required to raise the temperature of 1 lb of water 1 °F):

Units: BTU/hr • ft² • °F/ft or BTU/hr • ft • °FFurther, k_{snow (loose)} = 0.06, k_{snow (compact)} = 0.20.

In the range of water contents (5 to 10%) and dry densities (125-135 lb/ft³) commonly encountered in embankments and pavement base courses, thermal conductivity is very sensitive to moisture content and soil type. Soil thermal conductivities can be obtained from Figures 1 through 3 (from Kersten, 1949^[1] and Air Force, 1966^[2]):

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