One of the quickest ways to calculate a percentage with a calculator is to convert the percentage into a decimal and multiply it by the number you’re trying to find the percentage of. For example, if you want to find 60% of 285, enter 285 x .6 into your calculator to get 171. To figure out what percentage a number represents out of a whole, divide the smaller number by the larger one and convert the resulting decimal number into a percent. For example, 171 ÷ 285 = 0.6 = 60%.