DIY Cost Tools
Concrete Column Calculator
Estimate concrete for multiple round columns or piers from diameter, height, count, waste, and bag yield.
How to use this calculator
- Replace the example values with your own measurements or planning assumptions.
- Keep every value in the unit printed beside its field.
- Select Calculate and review the result together with the formula and limitations below.
Formula and method
For each round column, volume is π times radius squared times height. Multiply by column count and waste, then divide by bag yield.
Results are hidden whenever an input changes or validation fails, so an old answer cannot be mistaken for a current calculation.
Worked example
Number of columns = 4; Column diameter = 12 in; Column height = 8 ft; Waste allowance = 10 %; Yield per bag = 0.6 ft³. The calculator returns Concrete required = 27.646 ft³; Concrete required = 1.024 yd³; Exact bag requirement = 46.077 bags; Whole bags to buy = 47.
The worked example uses the same default values displayed in the calculator.
Limitations and safety
Frequently asked questions
Can I use this to choose a column diameter?
No. Use dimensions from approved plans or a qualified designer; this tool only estimates material for entered dimensions.
Why might the real result differ?
This is a volume estimate, not a structural design. Column diameter, reinforcement, embedment, soil, loads, and inspection requirements need qualified review.
How should I round the answer?
Keep extra precision while planning, then round up when purchasing whole containers, bags, pieces, or stock lengths. Follow the output labels and supplier packaging.
Review notes and reference
Reviewed October 4, 2026. The formula was checked against the displayed worked example, and the script was tested for defaults, boundaries, invalid formats, condition-specific errors, and recovery. Reference: OSHA construction safety resources. Explanations and examples are original.