Convert Feet and Inches into Barrels

Hello, I have got two colums one is b8 which is feet and one is c8 which is inches. I also have this day by day for example, b8 and c8 are day 1 and b9 and c9 are day 2. What i need is the for example, b8 is 5' and c8 is 1" then b9 is 5' and c9 is 3". I need to be able to enter that 2nd day in and then calculate the feet and inches into barrels which is 1 inch=1.16 barrels. This is kinda hard to explain but if there is anyone who is smarted than me and know what i am talking about. PLEASE HELP!!! THANKS IN ADVANCE