Concrete Column Volume Calculator

How it is calculated

A round column is a cylinder, so the concrete volume is V = π × r² × h, with the radius r and height h both in metres. The tool shows the volume in cubic metres rounded to two decimals, and also in litres, V × 1000, rounded to a whole number. The litre figure is more useful for small columns, since a volume under about 0.005 m³ displays as 0.00 m³. Radius and height must be above zero. The result is the exact geometric volume of the finished column. It does not add an allowance for spillage, over-excavation in a pile hole or uneven formwork, and does not subtract the steel reinforcement, so extra concrete is usually ordered on top.

Common mistakes

• Typing the diameter instead of the radius. A 0.5 m wide column has a radius of 0.25, and using 0.5 makes the volume four times too large.
• Entering centimetres or millimetres. The boxes are in metres, so a 40 cm diameter column must be typed as a radius of 0.2, not 20.
• Rounding the radius too early. Since the radius is squared, rounding 0.225 up to 0.25 changes the volume by about 23 %.
• Ordering exactly the calculated volume. Real pours lose material to spillage and uneven forms, so a margin is normally added on top of the geometric figure.
• Using this for a square or rectangular column. A different cross-section needs its own formula, because π × r² only describes a circular section.