Question: how to calculate how much dirt is needed to fill a hole?
Answer: Calculate the volume of dirt needed to fill in the hole using pi (3.142) times the square of the radius times the depth. For this example, you would multiply 3.142 by the square of 30 by 30 to obtain the volume. This yields 3.142 times 900 inches times 30 inches, or 84,834 cubic inches.