Tube form volume
A tube form is estimated as a solid cylinder. The calculator uses the inside diameter you enter, the depth, quantity and waste factor.
If your form has a flared base or extra footing shape, estimate that added concrete separately.
Round forms
Sonotube Calculator
Estimate concrete for round tube forms, piers and cylindrical footings.
US units
10% default waste
Bag and yard estimates
Concrete estimate
Enter dimensions
Printable reference
Sonotube Concrete Bag Chart
Use this chart to sanity-check common straight tube forms before buying bagged concrete or discussing cubic yards with a ready-mix supplier.
Source note: counts assume a straight round tube, 10% waste, and approximate bag yields. Confirm inside diameter, fill depth, footing design and bag yield before checkout.
Estimate assumptions
- Estimates are for planning and ordering only.
- Bag counts are rounded up to whole bags.
- Ready-mix yards are rounded up to the nearest 0.25 cubic yard.
- Default waste is 10%. Increase it for uneven excavation, spillage, or complex forms.
- Verify structural work with a contractor, engineer, or supplier before pouring.
Common Sonotube examples
A 12 in diameter tube that is 48 in deep is about 3.14 cubic feet before waste. With 10% waste, that rounds to 6 bags of 80 lb concrete.
A 12 in diameter tube that is 60 in deep is about 3.93 cubic feet before waste. With 10% waste, that rounds to 8 bags of 80 lb concrete.
A 16 in diameter tube that is 48 in deep is about 5.59 cubic feet before waste. With 10% waste, that rounds to 11 bags of 80 lb concrete.
Quick tube-form table
- Deck pier: 12 in dia x 48 in deep3.14 cu ft before waste; 6 80 lb bags with 10% waste for 1 tube.
- Tall deck pier: 12 in dia x 60 in deep3.93 cu ft before waste; 8 80 lb bags with 10% waste for 1 tube.
- Large pier: 16 in dia x 48 in deep5.59 cu ft before waste; 11 80 lb bags with 10% waste for 1 tube.
- Three piers: 12 in dia x 48 in deep9.42 cu ft before waste; 18 80 lb bags with 10% waste for 3 tubes.
Tube form reminders
- Inside diameterUse the inside diameter or concrete-fill diameter, not the outside label if the product differs.
- DepthUse the actual concrete fill depth inside the tube.
- QuantityUse the number of tubes with the same diameter and depth.
- Base shapeEstimate bell footings, flared bases and pads separately.
Common next purchases
Concrete mix
Rebar
Tube forms
Mixing tools
Trowels and floats
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FAQ
How do I calculate concrete for a Sonotube?
Use cylinder volume: pi times radius squared times depth. The calculator does that and converts to bags and yards.
What diameter should I enter?
Use the inside diameter of the form or the diameter that concrete will fill.
Does this include a Bigfoot-style base?
No. Estimate the tube and base separately if the footing shape changes.
How many 80 lb bags for a 12 inch Sonotube?
A 12 in diameter tube at 48 in deep rounds to 6 bags of 80 lb concrete with 10% waste. Change the depth in the calculator for your project.