Thermal conductivity is the ability of material to transfer heat and can be calculated as follows:
K = Watt / meter x 1 Kelvin
In material unit terms, thermal conductivity equals the amount of heat energy that penetrates a unit of material one meter thick where temperature difference on both ends of that material equals 1°K. Materials with high thermal conductivity are used as heat sinks. Materials with low thermal conductivity are used as insulators. Other units which are closely related to the thermal conductivity are in common use in the construction and textile industries. The construction industry makes use of units such as the R-Value (resistance value) and the U-Value (thermal transmittance).