Compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce the size, as opposed to tensile strength, which withstands loads tending to elongate. In other words, compressive strength resists compression (being pushed together), whereas tensile strength resists tension (being pulled apart). In the study of the strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently.
Some materials fracture at their compressive strength limit; others deform irreversibly, so a given amount of deformation may be considered as the limit for a compressive load. Compressive strength is a crucial value for the design of structures.