Concrete calculator
Concrete column
Round concrete-column volume, ready-mix order and bag-equivalent estimate.
Calculator result and formula
Ready-mix order: 0.25 yd³
Formula: π × (diameter ÷ 2)² × height × count ÷ 27 × (1 + waste)
Formula ID: CONC-COLUMN-001 · Version 1.0.0.
Inputs
- Column diameter: Inside diameter of the form Default: 12.
- Column height: Finished concrete height Default: 48.
- Number of columns: Count identical round columns Default: 1.
- Waste factor: Allowance for placement and site conditions Default: 10.
How this calculator works
This calculator applies the cylinder-volume formula to identical round concrete columns, then shows a ready-mix order and bag-equivalent estimate after allowance.
- Measure the inside form diameter and finished concrete height.
- Enter the number of identical columns; calculate non-identical columns separately.
- Use the rounded result as a supplier-quote starting point and confirm structural requirements independently.
Worked example: Example: one 12 in diameter column at 48 in high contains about 1.16 ft³. With 10% allowance, the ready-mix quantity rounds to 0.25 yd³.
Assumptions and limitations
- Each column is treated as a right circular cylinder.
- All entered columns are treated as identical.
- Ready-mix quantity is rounded to the next 0.25 yd³ after allowance.
Common questions
- Does this size a column or footing?
- No. Column dimensions, reinforcing, load design and local requirements require responsible professional review.
- Why are quantities rounded up?
- Ready-mix ordering and bag purchasing use practical increments; a visible allowance helps reduce a material shortfall.
Reference notes
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