How Many 80 lb Bags of Concrete in a Yard?
It takes 45 bags of 80 lb concrete to make one cubic yard. A cubic yard is 27 cubic feet, and each 80 lb bag yields about 0.60 cubic feet, so 27 divided by 0.60 is 45 bags. Here is the math in plain terms, the yield for every bag size, and how to compare bag quantities with a ready-mix order.
Key takeaways
- One cubic yard of concrete needs 45 bags of 80 lb mix, since 27 cubic feet divided by 0.60 cubic feet per bag is 45.
- An 80 lb bag yields about 0.60 cu ft, a 60 lb bag about 0.45, a 50 lb bag about 0.375, and a 40 lb bag about 0.30.
- By bag size per cubic yard: 45 bags of 80 lb, 60 bags of 60 lb, 72 bags of 50 lb, or 90 bags of 40 lb.
- The concrete calculator converts a measured pour into 80 lb and 60 lb bag counts using its stated yields; verify the selected product data sheet before ordering.
- Compare the cost and handling of 45 specified 80 lb bags with the supplier's actual one-yard ready-mix terms, including minimums, delivery and short-load fees.
The quick answer and the math
You need 45 bags of 80 lb concrete to make one cubic yard. The number comes from two facts that never change: a cubic yard holds 27 cubic feet, and an 80 lb bag of standard mix yields about 0.60 cubic feet once water is added.
bags per yard = 27 cu ft ÷ yield per bag (cu ft)27 ÷ 0.60 = 45 bags of 80 lbThat 45 figure is exact, with no allowance for spillage or an uneven base. In practice, buy a few extra so you never come up short mid-pour, because you cannot top up a slab once it starts to set.
Bag yields and number of bags by size
Not every bag is 80 lb, and the smaller the bag, the more of them a cubic yard swallows. The yield printed on the bag is what matters: it is the volume of finished concrete, not the dry weight. QUIKRETE and Sakrete both list about 0.60 cu ft for an 80 lb bag of standard 4000 psi mix.
| Bag size | Yield (cu ft) | Bags per cubic yard |
|---|---|---|
| 80 lb (36 kg) | 0.60 | 45 |
| 60 lb (27 kg) | 0.45 | 60 |
| 50 lb (23 kg) | 0.375 | 72 |
| 40 lb (18 kg) | 0.30 | 90 |
So the same cubic yard of concrete is 45 bags of 80 lb, 60 bags of 60 lb, 72 bags of 50 lb, or 90 bags of 40 lb. The 80 lb bag gives the greatest volume per bag in this table and therefore requires the fewest bags to handle.
How many 80 lb bags of Quikrete make a yard
The answer is the same 45 bags, because Quikrete Concrete Mix (product No. 1101) is rated at a 0.60 cu ft yield for the 80 lb bag, exactly the industry standard. Sakrete and other major brands publish the same figure for their standard mixes.
Watch out for specialty products though. Fast-setting, high-early-strength, and crack-resistant blends can yield slightly differently, so always read the yield on the actual bag rather than assuming 0.60. If you would rather skip the arithmetic, enter your slab size in the concrete calculator and it returns the bag count for 40, 60 and 80 lb mix at once.
How many bags for a 10x10 slab
A 10 by 10 ft slab at 4 inches thick needs about 1.23 cubic yards, or 1.36 with a 10% waste allowance. In 80 lb bags that is roughly 62 bags once you round up for waste, or 56 bags at the bare minimum with no contingency.
The volume math is simple: 100 square feet times 0.333 feet of thickness is about 33.3 cubic feet, which is 1.23 cubic yards. If your project is a different size, the broader guide on how many bags of concrete in a yard walks through the same method for any slab.
| Slab (4 in) | Cubic yards (+10%) | 80 lb bags |
|---|---|---|
| 8 × 8 ft | 0.87 | 40 |
| 10 × 10 ft | 1.36 | 62 |
| 12 × 12 ft | 1.96 | 88 |
Comparing bag quantities with a ready-mix order
Why an improvised dry-pour method is not a mix specification
The phrase is informal and does not identify a controlled concrete specification or approved placement method.
Follow the selected bagged product's mixing, placement and curing instructions. Do not use an improvised dry-pour method where concrete performance is required.
Frequently asked questions
How many 80 lb bags of concrete are in a yard?
How many 80 lb bags of Quikrete make a yard?
How many bags of concrete do I need for a 10x10 slab?
How should I compare bags with a ready-mix order?
Can I place bagged concrete without controlled mixing?
Sources and references
These references and structured source records support the method and material data used on this page.
- QUIKRETE Concrete Mix No. 1101 data sheet (0.60 cu ft yield)
- Sakrete: Estimating bagged concrete jobs
- Concrete (Wikipedia)
- Concrete cost per yard, data (Angi)