How Many Bags of Concrete in a Cubic Yard (40, 50, 60 and 80 lb)

A cubic yard of concrete takes 45 bags of 80 lb mix, 60 bags of 60 lb, 72 bags of 50 lb or 90 bags of 40 lb, with no waste allowance. Every count in that sentence follows from two numbers: a cubic yard is 27 cubic feet, and an 80 lb bag yields 0.6 cubic feet once it is mixed. Half a yard is 23 bags of 80 lb; a quarter yard is 12.

Slab / FootingRound Column / Post

Length (ft)

Width (ft)

Thickness (in)

Waste buffer (%)

Bag size

40 lb50 lb60 lb80 lb

Price per cubic yard ($ (optional))

Volume

33.3 cu ft

Ready-mix (incl. waste)

1.36 cu yd

80 lb bags needed

62

Estimated cost

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Bags needed by bag size

Bag size	Bags needed
40 lb	123
50 lb	98
60 lb	82
80 lb	62

Includes a 10% waste buffer. Ready-mix concrete is typically sold in quarter- or half-yard increments. Round up when ordering.

Bags per yard, half yard, quarter yard and cubic foot

Everything else on this page hangs off this table. The yard, half yard and quarter yard columns are rounded up to whole bags, since a store will not sell you 22.5 of them. The bags per cubic foot column is the multiplier for any volume that is not one of those three.

Bag size	Yield per bag	Bags per cubic foot	Quarter yard (6.75 cu ft)	Half yard (13.5 cu ft)	Full yard (27 cu ft)
40 lb	0.3 cu ft	3.33	23	45	90
50 lb	0.375 cu ft	2.67	18	36	72
60 lb	0.45 cu ft	2.22	15	30	60
80 lb	0.6 cu ft	1.67	12	23	45

Two of the rounded figures are worth noticing. A half yard of 80 lb bags is 22.5 bags on paper and 23 at the register, and a quarter yard is 11.25 bags, which becomes 12. The 50 lb and 60 lb rows both land on whole numbers at every size (18, 36 and 72 bags, and 15, 30 and 60), which makes them the easiest to scale mentally; the 40 lb row only misses at the quarter yard, where 22.5 bags becomes 23.

To use the multiplier column, work in cubic feet and round once at the end. A pour of 20 cubic feet in 80 lb bags is 20 times 1.67, which is 33.4, so 34 bags. The same 20 cubic feet in 60 lb bags is 20 times 2.22, 44.4, so 45 bags. Rounding each bag size separately matters because the leftover fraction differs: 34 bags of 80 lb gives you 0.4 cubic feet to spare, while 45 bags of 60 lb gives you 0.25.

None of these counts include a waste buffer. The concrete calculator adds 10 percent before it rounds, which is why its yard figure for a pour comes out at 50 bags of 80 lb rather than 45.

Where the 27 comes from, and why a bag’s weight is not its volume

A yard is 3 feet, so a cubic yard is 3 by 3 by 3, or 27 cubic feet. That one number sits inside every bulk formula on this site, and the construction unit conversions guide covers the shortcut that folds it together with the inches-to-feet conversion.

The bag side is the part people find odd. An 80 lb bag is sold by weight because dry mix is a powder plus aggregate, and weight is the only thing a scale at the plant can check. The volume it becomes is fixed by how dense the finished concrete is. Normal-weight concrete comes in around 145 lb per cubic foot. Put 80 lb of dry mix and about 3 quarts of water, roughly 6 lb, into 0.6 cubic feet and you get about 143 lb per cubic foot. The yield is simply the bag’s mass divided by concrete’s density, and that is why no 80 lb bag will ever make a full cubic foot.

The same arithmetic explains the four yields. Each bag size yields in proportion to its weight: 0.6 cubic feet per 80 lb is 0.0075 cubic feet per pound, and 40, 50 and 60 lb at the same rate give 0.3, 0.375 and 0.45. Products vary a little, and a mix with lightweight aggregate or a different cement content will print a different yield on the bag. When the bag states a yield, that figure overrides the table; the counts here use the figures most general-purpose mixes print.

Pallets: what a full one typically holds

Retailers stack 80 lb bags about 42 to a pallet and 60 lb bags about 56 to a pallet. Those are typical counts, not standards, and they vary by store and by product, so check before you plan a delivery around them.

Taken as typical, one pallet of 80 lb bags is 42 times 0.6, or 25.2 cubic feet, just short of a yard. A yard is therefore a full pallet plus 3 bags, and with the 10 percent buffer it is a pallet plus 8. A pallet of 60 lb bags at 56 is 25.2 cubic feet as well, which is not a coincidence: both pallets are built to a similar total weight, 3,360 lb of mix in each case.

That weight is the practical point. A pallet is not something a pickup carries casually, and a store’s delivery is the usual route for anything past a dozen bags. Have it set down on the hard surface closest to the pour. A pallet on a lawn in the rain is a pallet of half-set bags by the weekend.

The cost crossover: where the truck beats the bags

At typical 2026 retail, an 80 lb bag of general-purpose mix runs about $5 to $8. One yard at 45 bags is therefore roughly $225 to $360 for the concrete alone, before tax, delivery, the water and the better part of a day mixing it. Delivered ready-mix in 2026 is roughly $120 to $180 per yard, so on a straight per-yard comparison the truck costs about half as much.

The comparison is not straight on small orders. Plants charge a short-load fee below a few yards, and that flat charge on a one-yard order can bring the delivered price back up to what the bags cost, which is why bags remain the right call for small pours. The crossover sits somewhere between one and two yards depending on the plant’s minimums and fees. Below a yard, buy bags. Above two yards, order the truck. In between, price both, and count the labor as real money: 90 bags is a long day for two people. The concrete slab cost guide runs that comparison by slab size.

There is one more consideration that is not about price. A slab wants to be poured in one continuous operation so that it sets as one piece. Bags are mixed in batches, and on a large slab the first batches can start to stiffen before the last go in, which leaves a cold joint through the slab. For posts, piers, steps and small pads, batches are fine. For a slab over about a yard, the truck’s advantage is as much about getting it all down at once as about the price.

Mixing effort: what a yard of bags asks of you

An 80 lb bag takes about 3 quarts of water. Forty-five bags is roughly 135 quarts, call it 34 gallons, so for anything beyond a handful of bags the water comes from a hose with a marked bucket, not from carrying it. Measure it. The most common bagged-concrete failure is a mix made too wet because wet is easier to shovel, and the strength lost that way does not come back.

A wheelbarrow mixes one bag comfortably and two with effort. A rented drum mixer typically takes two or three 80 lb bags per batch and turns a yard into an afternoon rather than a weekend. Either way the limit is working time: each batch has to be placed and finished before it stiffens, so plan the pour in sections that one batch covers, and have the next bag open before the mixer is empty.

Weight is the other half of the effort. The dry mix for one yard is 45 times 80, or 3,600 lb, every pound of which gets lifted at least twice, once into the mixer and once as wet concrete into the form. A quarter yard, 12 bags, is a reasonable solo job. A full yard is a two-person job with a mixer, and a yard and a half is where most people who have done one once decide to call the plant next time.

Common pours expressed in bags

The site’s calculators add a 10 percent buffer and round each pour to whole bags, so the counts below are higher than a bare table conversion.

Pour	Concrete with 10% buffer	80 lb bags	60 lb bags
4x4 fence post, 10 in hole, 30 in deep	1.5 cu ft	3	4
Ten of those posts, rounded per hole	15 cu ft	30	40
12 in Sonotube pier, 48 in deep	3.46 cu ft	6	8
16 in Sonotube pier, 48 in deep	6.14 cu ft	11	14

Post holes are where bagged concrete makes the most sense, because each hole is a small pour that stands on its own and a run of them can be set one at a time. The fence posts, footings and Sonotubes guide carries the full per-hole table with 50 lb bags as well, and the rule for sizing the hole in the first place.

Slabs go the other way. Even a modest shed pad runs to dozens of bags, and the shed slab guide gives each pad size from 8x8 to 16x20 in both bags and yards so you can see where the count tips past a pallet. The slab thickness guide works a 12x12 slab through at 4, 5 and 6 inches, and the 4 inch version alone comes to 88 bags of 80 lb, which is the clearest illustration of why slabs get trucks and posts get bags.

Bags that look like concrete mix and are not

Several products sit on the same shelf in the same size of bag and do not follow this table.

Mortar mix and sand or topping mix contain no coarse aggregate. They are for laying brick and block or for patching, and their coverage is quoted per joint or per square foot at a given thickness rather than as a yield. The concrete block calculator handles the mortar side of a wall.

Fast-setting post mix is a concrete mix with an accelerator, and its yield per bag is typically close to the standard figure, but confirm it on the bag before reusing the counts above.

Core fill and grout are a high-slump product for filling block cores, not a substitute for concrete mix and not substituted by it. The mortar, grout and core fill guide sets out how those three products differ and how each is measured.

The yard-to-bag arithmetic itself transfers to any bagged bulk material once you know the bag’s volume. The mulch calculator does it for 2 cubic foot bags of mulch, and the paver calculator reports base and bedding sand in cubic yards, which convert the same way for a typical 0.5 cubic foot bag of paver base: 27 divided by 0.5 is 54 bags to the yard. The only number that changes from material to material is the one printed on the bag.