www.quikrete.com/calculator/main.asp

... calculator to help you determine the number of bags of QUIKRETE® Concrete
Mix, Mortar Mix, ... Enter the size of the slab you want to build in square feet.

www.lowes.com/cd_Concrete Pad Calculator_100901113_

Enter the dimensions below to calculate how many bags of concrete you need.
After entering the dimensions of the pad, click on "Calculate" and the calculator ...

www.sakrete.com/products/calculators.cfm

Calculate how much of a Sakrete product you need.

www.calculator.net/concrete-calculator.html

Several calculators to estimate the amount of concrete you will need based on ...
be used to estimate the volume and weight of the concrete you will need for the
size, ... and you can purchase pre-mixed concrete in 60-pound or 80-pound bags
.

www.concretenetwork.com/concrete/howmuch/calculator.htm

Calculate the amount of concrete you need in cubic yards and concrete bags.
Concrete ... Calculate Concrete Slab and Footing Pours ... Slab Dimensions.

www.blocklayer.com/concrete/concrete-premixeng.aspx

Calculate Number of Bags of Pre-Mix Concrete Mix for Round and Square
Footing Holes and Small Concrete Slabs.

www.blocklayer.com/concrete/concrete-premix.aspx

Calculate Number of Bags of Premix Concrete needed for Round and Square
Footing Holes and Small Concrete Slabs.

www.schlosserconcrete.com/Concrete-Calculator.html

Ready-mixed concrete is sold by volume measured in cubic yards. If you can
determine the area of your concrete project (length x width for rectangular
projects) ...

www.inchcalculator.com/concrete-calculator/

The concrete calculator will determine the cubic yardage and the number of pre-
mixed bags of ... Calculate the concrete yards or number of concrete bags
needed to pour a slab, patio, footing, .... Convert dimensions to feet if they aren't
in feet.