Percentages are the product when dividing two numbers and multiplying by 100 per cent. Microsoft Excel allows for easy math calculations and for formatting a number as a percentage. This is particularly useful when trying to make many calculations in a short amount of time or seeing how calculations fluctuate based on a change in variable.

Open Excel, and in cell A1 type the numerator. In cell B1 type the denominator. For example, for 75 per cent, in A1 type "3" and in B1 type "4."

Type "=a1/b1" in cell C1. In the example, C1 will result in 0.75.

Right-click cell C1, then click "Format Cells." Under the "Number" tab, click on "Percentage." Choose how many decimal places you want to take the percentage to. Hit OK. The number is now formatted as a percentage.