An 80 pound bag of concrete makes about 0.022 cubic yards, or 0.6 cubic feet. Divide the bag yield by 27 to get cubic yards. A cubic yard is about 45 of these bags.
The conversion
0.6 cubic feet divided by 27 is 0.0222 cubic yards. A 60 pound bag (0.45 cubic feet) is about 0.0167 cubic yards. A 40 pound bag (0.3 cubic feet) is about 0.0111 cubic yards.
So one yard is 45, 60, or 90 bags depending on the bag size.
Using this in your project
Find the volume of your project in cubic yards, then divide by 0.0222 to get the number of 80 pound bags. A 6 foot by 6 foot slab at 4 inches thick is 12 cubic feet, or 0.44 cubic yards, which is about 20 bags.
Or use the calculator on the concrete page. It shows the bag count directly.
Why labels differ
The yield printed on a bag is based on a standard amount of water and a normal mix. If you mix wetter, you get slightly more volume and weaker concrete. If you mix drier, you get less.
Cubic yards in a bag of concrete
| Bag weight | Cubic feet | Cubic yards |
|---|---|---|
| 40 lb | 0.30 | 0.0111 |
| 50 lb | 0.375 | 0.0139 |
| 60 lb | 0.45 | 0.0167 |
| 80 lb | 0.60 | 0.0222 |
Frequently asked questions
How many cubic yards in an 80 pound bag of concrete?
About 0.022 cubic yards.
How many cubic feet in an 80 pound bag?
About 0.6 cubic feet.
How many 80 pound bags for 2 yards?
About 90 bags.
How many bags for a 10 by 10 slab?
About 56 bags at 4 inches thick.