Volume is the measurement of the amount of space in an object, and is calculated in cubic units, such as cubic feet or cubic centimeters. Calculating the volume of a hole is often necessary when determining the amount of material needed to fill it or planning a well. Using the volume formulas for basic geometric shapes, it is easy to calculate the approximate volume of round and rectangular holes. A short hole can be measured with a yard stick or tape measure, while deeper holes will require an alternative method.
Measure the distance across the hole, and then divide this value by two. This is the hole’s radius. (Note: After obtaining measurements, remember to convert the units to feet.)
Multiply the radius value by itself. For example, if the radius equals 4 feet, multiply 4 x 4. Multiply the resultant value by Pi (3.14). This is the measurement of the hole’s base.
Stick the measuring tool into the hole to measure the height. If the hole is very deep, lower a rope/string into the hole until it reaches the bottom. Mark the string at the spot where it is level with the top of the hole. Measure the height marked on the string using a yardstick or tape measure.
Multiply the height by the base measurement to determine the hole’s volume.
Measure one side of the hole to determine its width. Measure the adjacent side to determine the length.
Lower the measuring tool into the hole and measure the height. Convert all measurements to feet before proceeding.
Multiply the width by the length. Multiply the resultant value by the height to calculate the volume.
Always remain consistent with measurement units. If you use more than one type of measuring tool, convert all measurements to the same unit. For example, inches cannot be multiplied by feet or yards.
These calculations are intended for measuring a hole with a fairly uniform cylindrical or rectangular shape. Using these formulas for irregular shapes will result in an inaccurate measurement.