Meet Your New Percentage Calculator

Three different percentage problems, three formulas

People searching "percentage calculator" usually mean one of three distinct calculations. This page covers all three with a separate formula and worked example for each.

1. Percent of a number

Formula: (percent ÷ 100) × number. Enter 20 for the percentage and 250 for the number, and the calculator returns 20% of 250 = 50. This is the calculation behind tips, discounts, and sales tax on a known price.

2. Percentage change between two values

Formula: ((new − old) ÷ old) × 100, rounded to two decimals. Enter 50 as the "From" value and 65 as the "To" value, and it returns The percentage change is 30.00% — a 30% increase. If the new value is lower than the old one, the result is negative (a decrease). A "From" value of 0 is rejected, since dividing by zero is undefined.

3. What percent one number is of another

Formula: (part ÷ total) × 100, rounded to two decimals. Enter 45 as the part and 60 as the total, and it returns 45 is 75.00% of 60. This is the calculation for test scores, quota progress, or budget usage.

Which one do you need?

If you know a percentage and a number and want the resulting value, use the first box. If you have two numbers and want to know how much one changed relative to the other, use the second. If you have a portion and a whole and want the portion expressed as a percentage, use the third.