Concrete is a common foundation material for many homes, sheds and other buildings. Large concrete foundations typically require the use of a commercial company to pour concrete. Small foundations --- such as sheds and outbuildings --- need only a few bags of concrete and a wheelbarrow. Before pouring the concrete, you will need to measure the foundation area to determine how much is needed. Convert measurements into square yards, as that is how many contractors sell concrete.
Measure the length and width of the foundation area. For odd-shaped foundations, measure each square or rectangular area.
Determine the depth of the foundation. Take a measurement from the foundation form or simply an estimate for recommended depth.
Multiply the length and width for each area measured. Multiply these figures by the depth of the foundation. Add these figures.
Divide the figure from Step 3 by 27 to determine the total cubic yards of concrete needed for the foundation.