Newbie question...Using Access 2000 in XP. I have searched here and in other forums and found this discussed, but never resolved. I am trying to run a report that will display the vehicle's mpg. Each time fuel is purchased, the user enters total $ amount, cost per unit, odometer reading, and checks a yes/no box to indicate wether or not this was a fillup, or just a partial fill of the fuel tank. I am trying to make the report where it figures the mpg at each fillup. Therefore, the report has to add any partial fills to the eventual fillup and subtract the odometer reading from the last fillup from the odometer reading of the current fillup, ignoring the odometer reading(s) from the partial fill(s). I have attached a reduced sample. Any help appreciated.