Average fuel cost

[craigous]

I use an app at the minute called fuel economy to work out my average daily fuel costs but would like it entered auto into the relevant field. the details I enter into the fuel economy app are Miles travelled, Vehicles MPG & Fuel cost per litre which then gives me my average fuel cost. & I then enter manually for my daily work record. Would be nice if I could enter my daily mileage & this updated the average fuel cost without having to enter it manually. Had 1 problem solved on here so looking to all you excel gurus out there to show me the way because I don't have a clue.. Thanks in advance...