`WCR = (3.5" quarts") / (0.6 " cubic feet")`

0.194950810185185

The Water to Concrete Ratio is 0.194950810185185 real. 

This ratio was derived from the recommendation of 3.5 quarts per 80 pound bag on the labelling of Sakrete 80lb bags of concrete.  An 80lb bag makes 0.6 ft³ of concrete

Bags of Concrete Calculators and Constants

• Cubic Yards of Concrete in a Slab
• Water Needed for Concrete 
• How many 40lb bags of concrete for so many cubic yards of concrete.
• How many 60lb bags of concrete for so many cubic yards of concrete.
• How many 80lb bags of concrete for so many cubic yards of concrete.
• Price of a 40lb bag of concrete.
• Price of a 60lb bag of concrete.
• Price of a 80lb bag of concrete.
• How many 40lb bags of concrete needed for a slab.
• How many 60lb bags of concrete needed for a slab.
• How many 80lb bags of concrete needed for a slab.
• Cubic Feet of Concrete in a 40lb bag.
• Cubic Feet of Concrete in a 60lb bag.
• Cubic Feet of Concrete in a 80lb bag.
• Cubic Yards of Concrete in a Circular Slab.
• Number of 40lb bags needed for a Circular Slab
• Number of 60lb bags needed for a Circular Slab
• Number of 80lb bags needed for a Circular Slab