A box-spring is a type of bed base typically consisting of a sturdy wooden frame covered in cloth, and containing springs. Usually the box-spring is placed on top of a wooden or metal bedframe which sits on the floor and acts as a brace. The box-spring is usually the same size as the much softer mattress which is placed above the box-spring. Working together, the frame, box-spring, and mattress make up a bed. It is common to find a box-spring and mattress being used together without the support of a frame underneath, the box spring being mounted directly on casters standing on the floor.

Queen size box-spring on metal bed frame

The purpose of the box-spring is threefold:

  • to raise the mattress' height, making it easier to get in and out of bed;
  • to absorb shock and reduce wear to the mattress; and
  • to create a flat and firm structure for the mattress to lie upon.

The first rectangular spring-cushioned wire frames to support mattresses did not have wood rims or cloth covers. These were called bedsprings. More and more box-springs are being made out of wood, then covered in fabrics. Wood makes a better support system for the newer memory foam and latex mattresses.[citation needed] The newest design in box-springs is the folding box spring made of wood and springs, then covered in fabric which can fold in half and can be sent by shipping and courier companies.

With the increasing height of mattresses, manufacturers now make box springs in different heights. Standard "high profile" box springs are 9 inches (23 cm) in height, whereas "low profile" box springs are between 5 and 5.5 inches (13 and 14 cm). The difference between the two heights is purely aesthetic and makes no difference in the support provided for the mattress.


Box-spring beds are popular especially in the United States and Canada.

Alternatively, in Japan futon mattresses are usually either placed on a bedframe or on the floor, without the use of springs; in Germany, mattresses are usually placed on a slatted base on the bedframe. This lath floor provides suspension, allows the mattress to ventilate, and can be designed to be vertically adjustable in order to elevate the legs and / or the torso.