Concrete Bag Calculator
Use our Concrete Bag Calculator to easily estimate the materials for your next project. Select your project shape, enter the dimensions, pick your bag size, and our calculator tells you the exact bag count to buy, with a 10% safety margin factored in.
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Dimensions
Settings
Estimation Results
Bags Needed (80lb)0 bags
Total Volume (Cubic Yards)0 yd
Total Volume (Cubic Feet)0 ft
Bag Size Comparison
40 lb
0
60 lb
0
80 lb
0
90 lb
0
For estimation purposes only. Verify structural calculations with a licensed engineer.
How It Works
Every bag of concrete has a yield — the amount of mixed concrete it produces once you add water. That number varies by bag weight:
| Bag Size | Approximate Yield |
|---|---|
| 40lb bag | 0.30 cubic feet |
| 60lb bag | 0.45 cubic feet |
| 80lb bag | 0.60 cubic feet |
| 90lb bag | 0.68 cubic feet |
These yields come directly from Quikrete and Sakrete product documentation. The calculator uses the same figures.
Bag Calculator FAQs
How many bags of concrete do I need?
You need exactly 45 bags of 80lb concrete to make 1 cubic yard. According to Quikrete's product specs, an 80lb bag yields 0.60 cubic feet. Since a cubic yard is 27 cubic feet, the formula is 27 ÷ 0.60 = 45 bags. For a 10x10 slab at 4 inches thick (1.23 yards), you need 1.23 × 45 = 56 bags.
How many bags is a yard of concrete?
You need exactly 45 bags of 80lb concrete to make 1 cubic yard. According to Quikrete and Sakrete specifications, one 80lb bag yields exactly 0.60 cubic feet. Since there are 27 cubic feet in a yard, the math is 27 ÷ 0.60 = 45 bags exactly.
How many bags of Quikrete in a yard?
There are 45 bags of 80lb Quikrete in a cubic yard. According to Quikrete's official product specs, an 80lb bag yields 0.60 cubic feet. The formula is 27 cubic feet ÷ 0.60 = 45 bags. For Quikrete 60lb bags (yield 0.45 cu ft), you need exactly 60 bags per yard (27 ÷ 0.45 = 60).
How many bags of concrete per fence post?
You need 1 bag of 80lb concrete or 2 bags of 40lb concrete for a standard 4×4 fence post in a 10-inch diameter hole that is 24 inches deep. The hole requires about 0.65 cubic feet of volume, minus the post volume (0.22 cu ft), leaving 0.43 cu ft of concrete needed.
How many 80lb bags of concrete on a pallet?
Quikrete 80lb bags are packed 42 bags per pallet. Sakrete packs 40 bags per pallet. When estimating for large projects, it's useful to know this to calculate pallet orders.
How many bags of concrete per m3?
One cubic meter = 35.31 cubic feet. At 0.60 cubic feet per 80lb bag, you need about 59 bags of 80lb concrete per cubic meter.