Concrete bag guide
How many cubic feet are in an 80 lb bag of concrete?
An 80 lb bag of standard concrete mix often yields about 0.60 cubic feet of mixed concrete. That number is product specific. Check the yield printed on the exact bag or technical data sheet before calculating how many bags to buy.
Calculate concrete for footings01 / Check the product
Bag weight does not guarantee concrete yield
The 80 lb label tells you the dry package weight. Yield tells you the approximate volume of mixed concrete the product makes. Mix design and aggregate grading can change that volume, so two 80 lb products can list different yields.
These manufacturer examples show why the product name matters. They are not interchangeable mix recommendations.
| Product and source | Bag size | Listed approximate yield |
|---|---|---|
| QUIKRETE Concrete Mix No. 1101 | 80 lb | 0.60 ft³ (17 L) |
| Sakrete High-Strength Concrete Mix | 80 lb | 0.60 ft³ |
| Sakrete Maximizer Concrete Mix | 80 lb | 1.0 ft³ |
The two standard examples list 0.60 ft³. The high-yield Maximizer product lists 1.0 ft³ at the same bag weight. Read the current package or data sheet instead of selecting yield from weight alone.
02 / Read the yield
Common QUIKRETE Concrete Mix bag yields
The QUIKRETE Concrete Mix No. 1101 data sheet lists several package sizes for the same product family. These values are useful examples, but they should not replace the data for another mix.
| Bag weight | Approximate cubic feet | Approximate litres |
|---|---|---|
| 40 lb | 0.30 ft³ | 8.5 L |
| 50 lb | 0.375 ft³ | 10.6 L |
| 60 lb | 0.45 ft³ | 12.7 L |
| 80 lb | 0.60 ft³ | 17 L |
| 90 lb | 0.675 ft³ | 19.1 L |
03 / Calculate whole bags
Divide the required volume by the listed yield
Suppose your estimated ordering volume is 12.4 ft³ and the exact product lists a yield of 0.60 ft³ per bag.
| Exact bag quantity | 12.4 ÷ 0.60 | 20.6667 bags |
|---|---|---|
| Whole bags to purchase | Round upward | 21 bags |
| Listed capacity of 21 bags | 21 × 0.60 | 12.6 ft³ |
| Capacity above entered volume | 12.6 − 12.4 | 0.2 ft³ |
Round upward because suppliers do not sell part of a bag. Keep any project allowance separate from this whole-bag rounding. The example uses listed approximate yield and does not guarantee the volume produced under every field condition.
04 / Use the right geometry
Calculate project volume before converting it to bags
For strip footings, rectangular pads, or circular pier footings, use the Concrete Footing Calculator. It calculates the volume from dimensions you already know, keeps your chosen allowance separate, and converts the order volume into whole bags using the product yield you enter.
For rectangular flatwork, the Concrete Slab Calculator calculates slab volume and material cost from known dimensions. Use the yield from the exact bag when planning bagged concrete.
This guide does not choose the correct concrete product, footing dimensions, slab thickness, strength, reinforcement, water quantity, or construction method. Follow the project requirements and the selected manufacturer's current instructions.
Next step
Enter the exact yield with your footing dimensions.
Choose the footing shape, calculate its concrete volume, then add the yield printed for the product you will buy.