Cement Bags Calculation

To calculate the number of bags of cement you need for a job you need to know two things. How many cubic feet of concrete does the job require. How many cubic feet of concrete does each bag produce. To calculate the number of cubic feet is Length x width x depth =cubic feet.. A 60 lb. bag of cemnt yields .45 cubic feet, a 80 lb. bag .60. Divide the number of cubic feet need by the yield per .