Concrete column calculator
For deck footings, piers and round columns. Enter the diameter, height and number of columns.
Measuring in feet and inches? Use the US version
Concrete needed
89 litres
- Bags of ready-mix
- 9 bags
- Cubic metres
- 0.089 m³
How it works
A column is a cylinder: π × radius² × height. The calculator converts the diameter from millimetres to metres, multiplies by the number of columns, adds your extra, and converts cubic metres to litres (× 1,000) for the bag count.
Example
With diameter 300 mm, height 1.2 m, number of columns 1, extra 5%, yield per bag 10 litres, the answer is 89 litres.
Tips before you buy
- Footings need to sit on firm ground, below the depth affected by frost and seasonal movement. Local guidance will tell you how deep.
- Tap or rod the form as you fill it to work out air pockets.
- Order a few extra bags. Holes and forms always take a little more than planned.
Common questions
How much concrete for a 300 mm column 1.2 m high?
About 85 litres, or 9 bags of a 10 litre yield with 5% extra.
How many litres per metre of a 300 mm column?
About 71 litres per metre of height.
How many litres are in a cubic metre?
1,000 litres.