Below you will find an "End Use Cost Calculator." To calculate the end-use cost from concentrated chemicals, divide the cost per gallon by the diluted quantity. For example, let’s assume you pay $25.00 for a gallon of cleaning concentrate, and it has a 1:256 dilution (0.5oz/Gallon). 1:256 yields 256 gallons of product. $25.00 ÷ 256 = $0.0976 per ready to use gallon.