How To Calculate The Percentage Of A Number

Percentages are one way to represent the relationship between a portion and the whole. Common uses for percentages include calculating the portion of sales an employee is responsible for, the portion of strikes a pitcher throws or the portion of questions a student gets correct on a test. Using percentages allows you to compare different ratios because the percentage is always out of 100, so all percentages have a common denominator.

Step 1

Identify the quantity of the part and the quantity of the whole. For example, if you wanted to determine what percentage of a company's sales came from a particular employee, the sales that employee generated would be the part and the total company sales would be the whole.

Step 2

Divide the part by the whole. In this example, if the employee generated $45,000 of sales and the company as a whole did $400,000, divide $45,000 by $400,000 to get 0.1125.

Step 3

Multiply 100 by the Step 2 result to find the percentage. In this example, multiply 0.1125 by 100 to find the employee was responsible for 11.25 percent of the company's sales.