Dimension refers to measurement of areas and objects. It is a mathematical figure expressed in units of linear measurement. Dimensions are used daily in planning and designing almost everything that is built or manufactured. Measurements are classified as one dimension, two dimensions or three dimensions. Length, width, and height are the basic kinds of measurements used to compute dimensions. Learning how to calculate dimension is easy and will give additional knowledge that can be used to improve life.

Measure any side of an object or surface in order to get a one-dimensional measurement. Any one side of a surface or object, be it the length, width or height by itself, is considered a single dimension. For example, a length of 1 foot is a single dimension and a width of 5 feet is also considered as a single dimension. Single or one-dimension measurements typically refer to lines of linear distance.

Measure any two sides (length, width or height) of an object or surface in order to get a two-dimensional measurement. For example, a rectangle that has a width of 3 feet and height of 4 feet is a two-dimensional measurement. The dimensions of the rectangle would then be stated as 3ft. (width) x 4ft. (height). These dimensions can be used to get the area of the rectangle by multiplying 3 feet by 4 feet, thereby giving a product or area of 12 square feet. Two-dimensional measurements typically refer to an area of a surface.

Measure all three aspects--the length, width and height--of an object to get a three-dimensional measurement. Continuing the example above, the 3 foot x 4 foot rectangle is the side of a box that has a length of 5 feet, so the dimensions are expressed as 3ft. (width) x 4ft. (height) x 5ft. (length). Three-dimension measurements refer to objects that have both surface and depth. They can be used to determine capacity--in the case of the box, 3 feet by 4 feet by 5 feet, or 60 cubic feet.