Hole Volume Calculator
The hole volume calculator finds the volume of a circular or rectangular hole. It also calculates the volume of concrete needed for concrete holes, considering the loss in the concreting process.
Concrete needed0.1164 cubic yards3.142 cu ft for 1 × 12 in diameter
Bags of mix680 lb concrete mix (0.60 ft³)
Each cylinder3.1416 cu ft0.11636 yd³
Radius6 in152.4 mm
Height4 ft1.2192 m
Cross-section area0.7854 sq ft
Weight when cured0.235 US tons
Cubic metres0.08896
The method
volume = π × radius² × height
Radius, not diameter, gets squared
Halve the diameter first. Using the diameter in π r² gives four times the right answer, which is the single most common mistake in column and tube work.
A 12-inch tube 4 feet deep holds about 3.14 cubic feet — roughly a tenth of a cubic yard, or six eighty-pound bags. Footings usually come in multiples, so work out one and multiply.