First, input at the end of column A (containing High Priority Customers Sales Out): =sum(A1:A20) This represents the sum of the values from cell A1 to cell A20. Then, to calculate the percentage of each cell in A, input the formula: =(A1/$A$21)*100 This formula will give you the percentage of A1, if you drag the box down to A20, you will have all the percentages of each sale from A1 to A20. Then, format the cell using the percentage number format with no decimal places. Select column D then right click, "format cells" and select number, adjust the number of decimal places.