In the course of running your business, you may find it necessary to perform calculations where you need to combine percents. Percents can be added directly together if they are taken from the same whole, which means they have the same base amount. This would be the case if you have a pie chart categorizing the expenditures in your office and wish to know the total percentage spent on office supplies and computer equipment. You would add the two percentages to find the total amount. You can use Microsoft Excel to to perform this operation.
Run Microsoft Excel. Open an old workbook, or create a new one.
Choose a cell that will contain a percentage, and type a number into it. For example, type 10 inside a cell in column A.
Format the number in column A so that it is a percentage. First, select the cell with the number.
Select the Home tab. Click Format then Format Cells. Select the Number tab, then click Percentage and the Okay button. The number in column B will change its display to a percentage. By default, Microsoft multiplies the number by 100; if necessary, modify the result so that it will display the amount, such as 10% instead of 1000%.
Type a different number in another cell and format it so that it is a percentage. For example, type 5 inside a cell in column B and change it to 5%.
Add the percentages together using the Sum function and display the result inside a different column. First, click on a cell in column C and click Fx in the formula bar. Select Sum, then Ok.
Fill in the text boxes next to Number1 and Number2. For instance, select the cell with the percentage in column A for Number1 and select the cell with the percentage in column B for Number2. Click Ok and the percentages will be summed. For example, if you combined "10%" and "5%" then "15%" will be displayed in column C.