how many bags of concrete would i need to do a 173 sqft circle?

An 80 lb bag of QUIKRETE® Concrete Mix yields 0.6 cubic feet when placed. Each QUIKRETE® Walk Maker® Building Forms requires approximately one 80 lb bag of QUIKRETE® Concrete Mix (No. 1101) to fill the mold. The nominal dimensions of the QUIKRETE® Walk Maker® Building Form is 2 feet by 2 feet by 2 inches thick. A 173 square feet circle will require the QUIKRETE® Walk Maker® Building Forms to be filled approximately 44 times, so 44 bags (of 80 lb each) of QUIKRETE® Concrete Mix would be required. Yields will vary based upon waste, uneven subgrade, etc.