How Many Bags of Concrete Are in a Cubic Yard?
A cubic yard swallows more bags of concrete than most people guess. Here are the 60 and 80 lb yields, the exact bags-per-yard math, and the point where a ready-mix truck wins.
Buying concrete by the bag feels simple until you run the numbers: a single cubic yard takes far more bags than almost anyone guesses. Here is exactly how many, and the point where hauling bags stops making sense.
Bag yields: what each bag actually makes
A bag of concrete is sold by its dry weight, but the number that matters for planning is its yield - the volume of mixed, wet concrete it produces. For standard concrete mix, the yields printed on the bag are remarkably consistent across brands:
- 80 lb bag ≈ 0.60 cubic feet
- 60 lb bag ≈ 0.45 cubic feet
- 40 lb bag ≈ 0.30 cubic feet
Notice these do not scale perfectly with weight - the mix and how much water it takes vary slightly - so always check the yield on the bag you are buying rather than assuming an 80 is exactly twice a 40. Fast-setting and high-strength mixes can yield a touch differently too.
The cubic-yard math
A cubic yard is a cube three feet on every side: 3 ft × 3 ft × 3 ft = 27 cubic feet. To find how many bags fill a yard, divide 27 by the bag's yield:
- 80 lb bags: 27 ÷ 0.60 = 45 bags
- 60 lb bags: 27 ÷ 0.45 = 60 bags
- 40 lb bags: 27 ÷ 0.30 = 90 bags
So the short answer is about 45 eighty-pound bags per cubic yard, or 60 of the 60 lb size. Most projects need only a fraction of a yard, so scale it down: a job that works out to a third of a yard (9 cubic feet) is roughly 15 of the 80 lb bags.
Why it is a lot of bags - and weight
Forty-five 80 lb bags is 3,600 pounds of material - nearly two tons you have to buy, load, transport, unload, and lift one bag at a time. On top of the weight there is the mixing: each bag needs measured water and a few minutes in a mixer or tub, and a full yard done by hand is a genuinely long, tiring session. There is also a timing risk. Concrete starts setting as soon as it is wet, so if you are mixing dozens of bags for one continuous pour, batches you mix early can begin to stiffen before the later ones are ready, leaving cold joints and an uneven surface. For anything beyond a small, forgiving pour, the bag count is telling you something.
When to switch to ready-mix
A useful rule of thumb: once a project approaches one cubic yard - roughly 40 or more 80 lb bags - a ready-mix truck is usually cheaper per yard, dramatically faster, and gives a single consistent batch with no cold joints. Below that, bags win on convenience and on not paying truck minimums; small footings, post holes, and a few fence posts are classic bag territory. Slabs, driveways, and wide patios almost always are not. If you are weighing the two, our guide on how much concrete you need walks through the volume formulas for slabs, footings, and columns and where the truck-versus-bag line falls for each.
Whichever way you go, add a 5 to 10 percent waste factor before you buy. Uneven subgrade, spillage, and a little over-excavation add up fast, and running short in the middle of a pour is far more expensive than a couple of spare bags.
Rather than dividing yields in your head, let Pour do it: enter your slab, footing, or column dimensions and it returns the cubic yards, the exact bag count at your chosen bag size, an estimated cost, and a flag for when you have crossed into ready-mix territory - imperial or metric, with a waste buffer built in.