Calculate percentages of numbers, percent change, and inverse percentages instantly. Use our free online calculator for quick math calculations.
What is X% of Y?
Find the percent increase or decrease between two numbers.
Our Percentage Calculator is a powerful, free web utility designed to simplify everyday mathematics. Whether you are computing sales tax, interest increases, discounts, or simple growth percentages, this tool handles calculations instantly in your browser. If you are working with rates or proportions, you may also find our Ratio Calculator or Fraction Calculator helpful.
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Enter the percentage and the base number in the first panel to find a percentage value, or enter starting and ending values in the second panel to determine the exact percent change. Calculations update in real-time as you type. Learn more about the mathematical history of percentages on Wikipedia.
To calculate the percentage of a number, multiply the number by the percentage value and then divide the result by 100. For example, to find 20% of 150: (20 * 150) / 100 = 30.
To calculate percentage change, subtract the old value from the new value, divide that difference by the old value, and then multiply by 100. Formula: ((New Value - Old Value) / Old Value) * 100.