Concrete
How Many Bags of Concrete Per Cubic Yard?
Exactly how many 40lb, 60lb, and 80lb concrete bags equal one cubic yard. Includes Quikrete yield constants, bag count table, and calculator link for jobs.
Official Bag Yields
Bag count starts with official yield. An 80lb bag of Quikrete yields 0.60 cubic feet, a 60lb bag yields 0.45 cubic feet, and a 40lb bag yields 0.30 cubic feet. One cubic yard contains 27 cubic feet. Divide 27 by the bag yield and round up to get bags per yard. That means one yard requires 45 bags of 80lb mix, 60 bags of 60lb mix, or 90 bags of 40lb mix. These constants should not be guessed because a small yield error becomes a large bag count error on bigger pours.
Bag Size Comparison
The 80lb bag is the most efficient because it produces more concrete per bag and usually costs less per cubic foot. The tradeoff is weight. Carrying and lifting 80lb bags all day can slow a solo worker down. The 60lb bag is easier to move and can be a good compromise for small slabs, steps, and repairs. The 40lb bag is light enough for smaller users and tight work areas, but it takes many more bags to make the same volume. Always round up because stores sell full bags and job sites waste material.
| Bag Size | Yield (cu ft) | Bags per Cubic Yard | Best For |
|---|---|---|---|
| 80lb | 0.60 cu ft | 45 bags | Most efficient — fewer bags to mix |
| 60lb | 0.45 cu ft | 60 bags | Easier to carry — good for solo work |
| 40lb | 0.30 cu ft | 90 bags | Lightweight — fence posts and small repairs |
When Bags Make Sense
Bags make sense for small projects where delivery fees would be larger than the material cost. Fence posts, mailbox posts, small pads, patch repairs, and isolated footings are common bag jobs. Bags also work when truck access is impossible. However, once a project approaches a cubic yard, the number of bags becomes serious. Mixing 45 to 90 bags takes time, water control, and labor. If the slab needs a continuous pour and a clean finish, ready-mix delivery may be the better choice even if the raw material cost is higher.
Cost and Labor Tradeoffs
Bag concrete is convenient, but the labor is real. Every bag must be moved, opened, mixed, placed, and cleaned up. Ready-mix concrete has delivery costs and minimums, but the material arrives already mixed and consistent. For a small repair, bags are usually cheaper overall. For a driveway section, patio, or garage slab, a truck can save hours and reduce finish problems. Compare total cost, not just price per bag. Include delivery, rental mixers, crew time, waste, and the risk of running short before deciding.
Get an Exact Bag Count
The easiest way to avoid bag-count mistakes is to calculate the project volume first and let the bag yields do the rounding. SpecMath shows 40lb, 60lb, and 80lb counts side by side so you can choose the size that fits your crew. Use the SpecMath Concrete Slab Calculator to check your estimate instantly before ordering material.
Use the Concrete Calculator
Use our Concrete Slab Calculator to check your estimate instantly.
FAQ
How many 80lb bags are in one cubic yard?
One cubic yard requires exactly 45 bags of 80lb Quikrete based on a 0.60 cubic foot yield. This is 27 cubic feet divided by 0.60 cubic feet per bag. Use the calculator for projects that are not exactly one yard.
How many 60lb bags make a yard?
One cubic yard requires exactly 60 bags of 60lb Quikrete based on a 0.45 cubic foot yield. The smaller bag is easier to carry but requires more bags. Round up for any partial yard.
Are bags cheaper than ready-mix?
Bags are often cheaper for small projects under one yard. Ready-mix is usually better for larger pours because it saves labor and improves consistency. Compare local material, delivery, and labor costs before choosing.