Concrete guide
Concrete Formula
The basic concrete formula is length times width times thickness. This gives you volume. For most concrete orders, that volume is converted into cubic yards.
Concrete Volume Formula
Volume = Length × Width × Thickness
Convert Cubic Feet to Cubic Yards
Cubic yards = Cubic feet ÷ 27
There are 27 cubic feet in one cubic yard. If your measurements are in feet, divide the final cubic feet result by 27.
Example Calculation
A 10 ft by 10 ft slab at 4 inches thick has a thickness of 0.333 feet.
10 × 10 × 0.333 = 33.3 ft³
33.3 ÷ 27 = 1.23 yd³
Common Mistake
The most common mistake is forgetting to convert inches into feet. A 4 inch slab is not 4 feet thick. It is 4 ÷ 12, or 0.333 feet.
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