Thickness

Thickness may refer to:
 * Thickness (graph theory)
 * Thickness (geology), the distance across a layer of rock
 * Thickness (meteorology), the difference in height between two atmospheric pressure levels
 * Thickness planer a woodworking machine
 * Optical thickness in optics
 * Thickness, a concept in the game Go
 * Thickness of a fluid, an informal name for viscosity