Formula used
Concrete volume = [π × (diameter ÷ 2)² × height ÷ 27] × (1 + waste ÷ 100), after converting diameter to feet
Worked concrete tube example
Concrete Tube Calculator example: π × (13.7 in ÷ 12 ÷ 2)² × 3 ft = 3.07 ft³. Applying 10% gives 0.13 yd³; round any bag conversion to whole packages.
From calculated volume to an order
Use the yardage for all identical tube forms, then apply a modest placement allowance that reflects the number and accessibility of the forms.
Where a concrete takeoff can drift
Tubes can be cut unevenly, bell at the base, or extend into a larger footing; those shapes should be measured and added separately.
Questions specific to this calculation
Which diameter and height define the concrete tube placement?
Measure the tube's inside diameter and its actual fill height. Do not use the outside printed diameter if the form manufacturer states a different inside size.