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Calculators & guides

Concrete Column Calculator

Estimate concrete for round columns, deck piers and cardboard tube forms.

Units

Geometry dimensions — schematic, not to scaleD (diameter)H
Schematic · not to scale · quantity repeats the entire solid

Concrete & bag assumptions

Density is the placed concrete density, not dry bag weight. Defaults are examples for normal-weight concrete. Bag weight does not determine yield; use the mixed yield printed on your product.

Estimate cost (optional · USD)

All cost fields are optional and user-entered. Ready-mix and bags are alternatives, never added together. No average or local prices are assumed — use a real quote. Labor per area is available only for shapes with a defined footprint.

Formula & solid model

Volume = π × (diameter ÷ 2)² × height × quantity

All lengths convert to metres before calculation. Blank waste = 0%. Zero dimensions or quantity produce zero volume. Display values are rounded; costs and bags use unrounded volumes.

Column · incl. 10% waste

You need approximately 0.256 cubic yards

6.912 ft³ · 0.196 m³ · 195.71 litres

Volume

UnitExact+10% waste
Cubic yards0.2330.256
Cubic feet6.2836.912
Cubic metres0.1780.196
Litres177.92195.712

Placed weight · incl. waste

1,036.73 lb / 470.25 kg

Density: 150 lb/ft³ · weight = volume × density

Selected premix bags · incl. waste

12 × 80 lb bags

Yield: 0.6 ft³ / bag · total volume ÷ yield, rounded up.

Estimate inputs & formula

Diameter: 12 in · Height: 8 ft · Number of columns: 1

Volume = π × (diameter ÷ 2)² × height × quantity

Estimate only, not engineering advice. Actual needs vary with subgrade, forms and spillage. Confirm final quantities and product yields with your supplier or contractor before ordering.

What this calculates

Each column is a cylinder. Enter the inside diameter of the form, the height and how many you are pouring.

Formula

Volume = π × (diameter ÷ 2)² × height × quantity

Worked example

Four 12 in tubes, 8 ft tall

  1. 1.π × 0.5² × 8 = 6.28 cu ft each
  2. 2.× 4 = 25.1 cu ft = 0.93 cu yd
  3. 3.Add 10%: about 1.02 cu yd

Common mistakes

  • Using radius where the formula expects diameter (or vice versa).
  • Forgetting the portion of the tube buried below grade.

Frequently asked questions

How many bags fill a 12 inch Sonotube?

A 12 in tube holds about 0.785 cu ft per foot of height — roughly 1.3 bags of 80 lb premix per foot.

Does this work for square columns?

For square columns, use the footing calculator with length and width equal to the column sides and depth equal to its height.