Definition of Firmness

Meaning of the Term as it Pertains to Mattresses

What is Firmness?

Firmness is a term used to describe the amount of resistance that pushes against the body when lying on a mattress. Considered the "feel" of the mattress, firmness describes the tactile change you sense immediately upon lying down. A mattress that has little "give" is considered firm, while a mattress you sink into is called soft or plush. Mattress firmness is typically classified in four categories: extra firm, firm, plush, and ultra plush.

Some shoppers confuse firmness with support, but the terms describe two entirely different qualities of a mattress. Support refers to the mattress's ability to resist pressure applied by the weight of the entire body. An essential function of a mattress, support allows the spine to rest in its natural shape for the entire night. Firmness refers to comfort and is entirely subject to personal preference. An easy way to remember the difference is to consider firmness as surface feel and support as inner foundation. Support and firmness do not affect each other. Both an extra firm mattress and an ultra-plush mattress can offer the same amount of support.