Concrete bag count

How it is calculated

Whole bags = ceil(required concrete volume ÷ mixed yield per bag); prepared volume from whole bags = whole bags × mixed yield.

Keep the full result when using it in another calculation. Results show up to three decimal places; very small positive results use scientific notation (for example, 1e-6). Whole bags round upward to complete units. No extra material for waste is added.

Find the yield for the product you will buy

Check the mixed-concrete yield on the package or current product data for the exact mix and bag size. Yield is the volume of concrete one bag produces after mixing. The number of pounds on the bag is its dry package weight, not the concrete volume it will produce.

Enter the concrete volume you need and the product’s stated yield in matching units. This calculator uses cubic feet, so convert a requirement in cubic yards by multiplying by 27 before entering it.

Understand the whole-bag result

For 40 ft³ of required concrete and a product yield of 0.60 ft³ per bag, 40 ÷ 0.60 = 66.67 bags. Because bags are purchased as whole units, the result is 67 bags, with a calculated mixed volume of 40.2 ft³.

The 0.2 ft³ difference comes from rounding up to whole bags. It is not a waste allowance. If you use an allowance, add it to the required volume once before calculating the bag count.

Before you use the result

• Use the yield listed for your exact product and bag size. Yield is the volume of mixed concrete one bag produces; dry bag weight is not a substitute. Product yields are approximate.
• The result rounds up to whole bags but adds no extra bag or waste allowance. It does not plan truck loads, mixer batches, mixing rates, or delivery and placement times.

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