Use the following yields per each bag size. Mark the area that will need concrete and divide it into smaller areas. Keep your figures written down on paper as you go.
Input length width and depth of the area.
Multiply the three dimensions together to find the number of cubic feet 05 feet x 12 feet x 12 72 cubic feet Divide the cubic feet by the number of cubic feet in a cubic yard 27 to find the number of cubic yards 72 27 267 cubic yards. Calculate the volume of concrete you need in cubic yards. The volume formula for a rectangular or square slab in cubic feet is height ft x width ft x length ft as seen in the figure below. Calculate the volume of the area after determining the shape of the area see the chart below by multiplying in the thickness of the concrete.