To calculate a percentage, you need to divide the part by the whole and then multiply by 100. The formula for calculating a percentage is: percentage = (part / whole) x 100 For example, if you want to find out what percentage of 50 is 10, you would divide 10 by 50 and then multiply by 100: percentage = (10 / 50) x 100 percentage = 0.2 x 100 percentage = 20% So, 10 is 20% of 50.