How to Calculate How Much Sand Is Needed for a Paver Job

Divide the area to be paved into simple shapes, such as rectangles, triangles and circles. Always use regular shapes when you can; they are easily measured and the math required to determine their surface areas is straightforward. The surface area of a rectangle is the length multiplied by the width, and that of a triangle is half the length multiplied by the width. The area of a circle is pi times the radius squared, where pi is usually given as 3.1415. For example, an irregular shape patio consisting of a square with a diagonal corner missing and a semicircular bay on one side consists of a rectangle and half a circle minus a triangle in one corner.

Calculate the surface area of each shape and then combine them to determine the total surface area. For example, a square with sides 20 feet long combined with a semicircle with a radius of 10 feet has a total surface area of 557.07 square feet because the square has an area of 400 square feet and the semicircle has an area of 157.07 square feet -- half a circle of surface area 314.14 square feet.

Multiply the total surface area by the depth of the sand expressed as a fraction of 1 foot. The result is the number of cubic feet of sand required as a bed for the paved area. For example, 1 inch is a 1/12 of a foot so the surface area multiplied by 1/12 equals the volume of sand required. For 557 square feet of paving resting on 1 inch of sand you require 46.42 cubic feet of sand -- 557 x 1/12 = 46.41(6).