Enter the length, width and height of a rectangular shape and get the volume in different units. See the formula, the graphic and the conversion factors for volume calculation. Use this volume calculator to calculate the volume for the three-dimensional geometrical shapes. It provides calculations for a volume in different units and also shows the formula to find the volume for a selected shape. Online volume of rectangle calculation. Use this simple geometry volume of rectangle calculator to calculate volume. Learn how to calculate the volume of a rectangular prism using the formula V = l × w × h, where l, w and h are the length, width and height of the prism. See solved examples and diagrams of different rectangular prisms.