Free Concrete Bag Calculator
Calculate how many bags of premixed concrete you need. Supports 80 lb, 60 lb, and 40 lb bags with accurate coverage values.
feet
feet
inches
Bags Needed
56
Total Volume33.33 cu ft
Total Volume1.23 cu yd
Bags Needed vs Length
How to Calculate Concrete Bags Needed
Formula
Bags = Total Cubic Feet / Coverage per Bag
For small projects under 1 cubic yard, bagged concrete is more practical. For larger projects, order ready-mix from a concrete plant.
Example Calculation
A 10 ft by 10 ft slab, 4 inches thick, using 80 lb bags.
- 01Depth in feet: 4 / 12 = 0.333 ft
- 02Volume = 10 × 10 × 0.333 = 33.33 cu ft
- 03Cubic yards = 33.33 / 27 = 1.23 cu yd
- 04Bags (80 lb) = 33.33 / 0.60 = 55.6 → 56 bags
Frequently Asked Questions
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How to Calculate Concrete Needed for Any Project
Learn how to calculate the exact amount of concrete needed for slabs, footings, columns, and other projects. Covers volume formulas, waste factors, and ordering tips.