How to Calculate the Cubic Feet of Concrete
- 1). Measure the length, width and depth in feet of the area to be filled with concrete.
- 2). Multiply the length by the width and the depth. For example, 20 feet long by 12 feet wide by .5 feet thick equals 120 cubic feet.
- 3). Divide the answer by 27 to convert into cubic yards. Using the above example, 120 divided by 27 equals 4.44 cubic yards.
- 4). Increase the total by 5 percent to ensure that you do not run short. In our example, 4.44 multiplied by 1.05 equals 4.66 cubic yards of concrete.
- 5). Prepare a place in advance where any leftover concrete may be used if necessary.