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Sonotube Concrete Calculator

Estimate the concrete needed for round tube forms using diameter, height and quantity. Get ready-mix volume, waste allowance and bag estimates in seconds.

US and metric units Ready-mix volume Bag estimates

Estimate concrete for round forms

Enter the inside diameter, concrete height and number of tubes for a complete project estimate.

Enter your project details

Choose a unit system, then add your tube dimensions and project quantity.

in
ft
in
qty
%
Use the actual inside diameter and the full height that will be filled with concrete. Bag yields are approximate, so check the product label before purchasing.

Your results

Enter your tube dimensions and click Calculate concrete to see total volume, conversions and bag estimates.

Project estimate
Concrete to plan for
0.00 yd³

Includes your selected waste allowance.

Per tube 0.00 ft³
Before waste 0.00 yd³
Waste added 0.00 ft³
Total tubes 1
Cubic feet 0.00 ft³
Cubic yards 0.00 yd³
Cubic meters 0.000 m³
Liters 0 L
Estimated bags 60 lb bags
0
Calculation steps
    About the tool

    What is a Sonotube concrete calculator?

    A Sonotube concrete calculator estimates the volume of concrete required to fill one or more round column forms. It converts your measurements into cylinder volume, adds your chosen waste allowance and shows practical ordering values.

    Cylinder-based calculation

    Uses the inside diameter and filled height of each round form to calculate concrete volume.

    Flexible unit systems

    Work in inches and feet or centimeters and meters without doing manual conversions first.

    Ordering-friendly results

    See cubic yards, cubic feet, cubic meters, liters and an approximate concrete bag count.

    How it works

    How to use the Sonotube concrete calculator

    The calculator turns a few project measurements into a complete concrete estimate.

    1

    Choose your units

    Select US / Imperial or Metric so you can enter measurements in the format used on your project.

    2

    Enter tube dimensions

    Add the inside diameter and the total height that will actually be filled with concrete.

    3

    Add quantity and waste

    Enter the number of identical tubes and choose a waste allowance for spills and small variations.

    4

    Review the estimate

    See ready-mix volume, unit conversions, per-tube volume and the estimated number of bags.

    Formula

    How Sonotube concrete volume is calculated

    A filled round concrete form is treated as a cylinder. The calculator finds one tube's volume, multiplies it by the quantity and then applies the waste percentage.

    From tube size to concrete order

    Start by dividing the diameter by two to get the radius. Square the radius, multiply by π, and then multiply by the filled height. For multiple tubes, multiply the single-tube volume by the total quantity.

    After the base volume is known, the selected waste allowance is added. The final result is then converted into common ordering units such as cubic yards or cubic meters.

    For bagged concrete, the calculator divides the final project volume by the approximate yield of the selected bag size and rounds up to the next whole bag.

    Cylinder volume formula

    Use the same unit for radius and height.

    V = π × r² × h
    V = concrete volume
    r = half of the inside diameter
    h = filled concrete height

    Project estimate notice

    This calculator provides a planning estimate. Actual concrete requirements can change because of field measurements, uneven bases, over-excavation, form tolerances, spills and the published yield of the specific concrete mix you buy.

    FAQ

    Frequently asked questions

    Common questions about estimating concrete for round tube forms and cylindrical posts.

    Measure the inside diameter and the height that will be filled. Use the cylinder formula V = π × r² × h, then multiply by the number of tubes. Add a waste allowance for a more practical ordering estimate.
    Use the inside diameter of the space that will actually be filled with concrete. The calculator estimates concrete volume, so the fill dimensions are what matter.
    Many projects include an extra allowance for spills, small measurement differences and uneven conditions. The calculator lets you choose the percentage that fits your project instead of forcing one fixed value.
    Yes. Enter the number of tubes in the quantity field. The calculator multiplies the volume of one tube by the full quantity before applying your waste allowance.
    Choose a bag size in the calculator and it will divide the final project volume by an approximate bag yield. Always check the yield printed on the concrete product you plan to buy because mixes can differ.
    Yes. The same cylinder-volume method works for straight, round concrete forms, piers and columns when you know the inside diameter and filled height.
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