Things You'll Need

Instructions

1

Determine the number of square feet that covers a given area. Measure the length of the space using a tape measure. Measure the width of the space with the tape. Multiply the length measurement by the width measurement using a calculator. The product is the number of square feet in the area. For example, if the length of a room is 18 feet, and its width is 8 feet, the room is 144 square feet (18 feet in length times 8 feet in width).
2

Divide the square footage measurement by 9. Because 1 yard is 3 feet long, a square yard is 3 feet by 3 feet, or 9 square feet. In the example, 144 square feet divided by 9 equals 16 square yards. So, the 144 square foot room described in the example is also 16 square yards.
3

Determine the number of cubic yards in a given space by including a depth measurement in your calculations. For example, if you wanted to pour a 3-inch thick slab of concrete into the room in Step 1, multiply the number of square yards you calculated -- 16 -- by the depth of the slab. Because there are 36 inches in a yard (3 feet per yard times 12 inches per foot), 3 inches is 0.083 yards (3 inches divided by 36 inches). Multiply 16 square yards by 0.083 yards of depth for 1.33 cubic yards.
4

Determine cubic yards from a square footage measurement. A 3-inch depth measurement is .25 feet (3 inches divided by 12 inches per foot). Multiply the room’s 144 square feet by .25 feet of depth for 36 cubic feet. Divide by 27 to convert cubic feet to cubic yards. Use 27 because a cubic yard is 3 feet long by 3 feet wide by 3 feet deep. The result is 1.33 cubic yards (36 cubic feet divided by 27 cubic feet per cubic yard).