How Many Bags of Concrete Are in a Cubic Yard?

Concrete bags are sold by dry weight, but a project needs a volume of mixed concrete. The number that connects them is the mixed yield on the exact product’s label. Use that yield before deciding how many complete bags to buy.

By CalcsteadUpdated September 22, 20264 min read

The short answer

Using QUIKRETE Concrete Mix No. 1101 nominal yields, one cubic yard needs 45 × 80 lb bags, 60 × 60 lb bags, or 90 × 40 lb bags before allowance. Half a yard needs 23 whole 80 lb bags. Other products may have different yields.

Use the concrete volume calculator

On this page

Bag yields and quantities for common volumes

One cubic yard contains 27 ft³. The referenced product lists nominal yields of 0.30 ft³ for 40 lb bags, 0.45 ft³ for 60 lb bags, and 0.60 ft³ for 80 lb bags. These values refer to this concrete mix; they do not apply automatically to mortar, sand mix or other specialty products.

Complete bags before any allowance

Every column is a separate alternative, not a combined purchase. Counts are rounded up once for the total required volume.

Required concrete	40 lb bags	60 lb bags	80 lb bags
0.25 yd³	23	15	12
0.5 yd³	45	30	23
1 yd³	90	60	45
1.5 yd³	135	90	68
2 yd³	180	120	90

The formula behind the bag count

Bags = required cubic yards × 27 ÷ nominal bag yield in ft³. Round the final result upward because a fraction of a sealed bag is not normally a purchasable unit. Keep unrounded values through the volume and allowance steps.

For one yard with 80 lb bags, 27 ÷ 0.60 = 45 bags exactly. For half a yard, 13.5 ÷ 0.60 = 22.5 bags, so the purchase is 23. That extra half-bag of nominal yield is purchase rounding, not a separate project allowance.

Add an allowance before rounding

An example 10% allowance on half a yard gives 13.5 × 1.10 = 14.85 ft³. Dividing by 0.60 gives 24.75 bags, so the purchase is 25. If you instead add 10% to the already rounded 23-bag count and round again, you would buy 26.

The difference comes from rounding at different stages. Our quantity method applies the allowance to the exact required volume, then rounds complete bags once. Select the allowance for the actual project and avoid adding it a second time to a calculator result that already includes it.

Worked example: a 10 × 10 ft slab

At an example 4-inch uniform thickness, the slab contains 10 × 10 × 4 ÷ 12 = 33.333… ft³. Without allowance, that is 55.555… nominal 80 lb bags, rounded to 56. With 10%, it becomes 61.111… bags, rounded to 62.

The slab chart linked below compares other footprints and thicknesses. Use the concrete calculator if your dimensions differ or you have several compatible sections. Additional footings and thickened edges must be included without double-counting the basic slab.

Choose a bag size for the complete job

A smaller bag changes the number of packages and the handling weight, even if the total concrete volume is the same. Compare cost per nominal cubic foot: bag price divided by its stated yield. Then compare the total cost of the rounded bag count, not only the unit rate.

For example, an invented $6 price for a 0.60 ft³ bag is $10 per nominal ft³. An invented $4.80 price for a 0.45 ft³ bag is about $10.67 per ft³. Transport, available stock and handling may still affect your choice; those prices are arithmetic examples only.

Check logistics before choosing bagged concrete

A one-yard order of 45 nominal 80 lb bags represents 3,600 lb of dry packaged product. The batch also requires mixing water and a placement plan, so dry bag weight is not the finished concrete’s weight. Check vehicle and equipment limits rather than treating the bag count as a safe transport load.

As the job grows, compare ready-mix delivery, minimum load charges, site access, mixing equipment and placement time. Calculate one required volume first, then compare supply alternatives against that same volume.

Common questions

Can I use the same count for 80 lb mortar bags?

No. Weight alone does not establish yield. Use the mixed volume stated for the exact product and divide the project’s required volume by that yield.

Should I round each small section separately?

If compatible sections share one purchase, add their exact volumes, apply the project allowance once and round the combined bag order. Separate purchases or different products require separate counts.

Sources and product references

QUIKRETE — Concrete Mix No. 1101 data sheet
Product-specific nominal yields: 0.30 ft³ for 40 lb, 0.45 ft³ for 60 lb, and 0.60 ft³ for 80 lb bags. Verify the label on the mix you buy.
NIST — SI units: volume
Reference for volume units. Coverage tables and worked examples on this page are Calcstead calculations, not product performance guarantees.

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