Cubic feet
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Concrete Column & Sonotube Calculator
Concrete Column & Sonotube calculator
Calculate concrete for round columns, piers and Sonotubes. Cubic yards, bags, ready-mix loads and weight — with a waste margin built in, nothing leaves your browser.
Dimensions
FIG. 01Volume ÷ 27 = cubic yards. Pros order to the nearest ½ yard and add a waste margin — running short mid-pour risks a cold joint.
You need
—cu yd
Order to nearest ½ yd → — · —
Cubic meters
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80 lb bags
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60 lb bags
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Est. weight
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Best buy
see above
How this is calculated
A round column is π × radius² × height. For a 12-inch (1 ft) diameter tube the radius is 0.5 ft, so each foot of height holds about 0.785 cubic feet. Multiply by the number of tubes using the quantity field.
cubic yards = volume in cubic feet ÷ 27 × (1 + waste%)
For the full method and sources, see the methodology page. Comparing buying options? Use the bags-vs-ready-mix calculator.
FAQ
How do I calculate concrete for a Sonotube?
A round column is π × radius² × height. For a 12-inch (1 ft) diameter tube the radius is 0.5 ft, so each foot of height holds about 0.785 cubic feet. Multiply by the number of tubes using the quantity field.
How many Sonotubes per bag of concrete?
A 12-inch tube 4 ft tall needs about 3.14 cubic feet — roughly six 80-lb bags. For several deep piers, a short-load ready-mix order is often cheaper and far faster than mixing bags.