Concrete Column Calculator
Calculate cubic yards of ready-mix concrete for a round structural column from its height and diameter, plus material cost per yard.
How this calculator works
A round structural column’s volume follows the cylinder formula — π × radius² × height — rather than a rectangular one. This calculator converts your entered diameter (in inches) to a radius in feet, multiplies by height, and converts the result to cubic yards for a ready-mix order.
Formula: Cubic feet = π × (Diameter in ÷ 24)² × Height ft. Cubic yards = Cubic feet ÷ 27.
Worked example
A 16-inch diameter column, 8 ft tall:
- Radius in feet: 16 ÷ 24 ≈ 0.6667 ft
- Cubic feet: π × 0.6667² × 8 ≈ 11.1701 ft³
- Cubic yards: 11.1701 ÷ 27 ≈ 0.41 yd³
- At $150/yd³, that’s $62.06 before waste — per column.
Cost reference
| Column size | Cubic yards | Cost at $150/yd³ |
|---|---|---|
| 8 in dia × 4 ft | 0.05 yd³ | $7.72 |
| 16 in dia × 8 ft | 0.41 yd³ | $62.06 |
| 32 in dia × 16 ft | 3.31 yd³ | $496.44 |
How to measure your column
Measure the column’s design diameter in inches and its full poured height in feet, taken directly from the structural drawing rather than an on-site guess. Structural columns are engineered elements — always verify diameter, reinforcement, and concrete strength against the engineer’s spec before ordering, and multiply this per-column result by your total column count for the full job quantity.
Frequently asked questions
What do the height and diameter fields mean for a column?
Height (ft) is the column's total poured height, and diameter (in) is the column's cross-sectional width — for a round structural column, that's the outside diameter of the concrete itself, not including any formwork thickness.
Is this calculator suitable for load-bearing structural columns?
This calculator estimates concrete volume for a round column of a given height and diameter only — it does not determine what diameter, reinforcement, or concrete strength (PSI) a structural column actually needs. Column sizing for anything load-bearing is an engineering decision based on the load carried, unsupported height, and applicable building code; always confirm dimensions with a structural engineer before ordering concrete for a structural column.
Why does this use cubic yards instead of bags like the sonotube calculator?
Structural columns are typically larger-diameter, taller pours than a sonotube footing, putting them in the range where ready-mix delivery is more practical than bagged mix — so this calculator returns cubic yards, the unit ready-mix suppliers price by. For a smaller-diameter form like a sonotube, use the sonotube calculator, which returns bag count instead.
Does a concrete column need rebar?
Yes — virtually all structural round columns are reinforced with vertical rebar in a circular pattern, tied together with spiral or hoop ties, sized and spaced per an engineer's design. This calculator estimates concrete volume only; rebar is a separate material and labor cost specified by the structural design.
How is column volume different from a rectangular pier or pilaster?
A round column's volume uses π × radius² × height, which for the same width and height contains noticeably less concrete than a square pier of matching outside dimensions (a circle inscribed in a square uses about 78.5% of the square's area). If your structure calls for a square or rectangular pier instead of a round column, use a standard rectangular volume calculator instead of this one.
Estimates only. Verify quantities with your supplier before purchasing.