Percentage Calculator
Work out percentages quickly and easily.
Mode 1: What is X% of Y?
Mode 2: X is what percent of Y?
Mode 3: Percentage change from A to B
What is a percentage calculator?
A percentage calculator is a free online tool that works out percentage problems in seconds. A percentage is simply a part of 100: 20% means 20 out of every 100. Instead of doing the sums by hand, you enter your numbers, click Calculate, and get an instant, accurate answer.
How to use this percentage calculator
Mode 1 — What is X% of Y? Enter the percent in the first box and the number in the second, then click Calculate. For example, enter 20 and 200 to find 20% of 200.
Mode 2 — X is what percent of Y? Enter the part and the whole, then click Calculate. For example, enter 50 and 200 to find that 50 is 25% of 200.
Mode 3 — Percentage change from A to B. Enter the starting value (From) and the new value (To), then click Calculate. The result tells you whether the value went up or down, and by what percentage. Use Reset at any time to clear all three modes and start again.
The formulas
Mode 1: X% of Y = (X ÷ 100) × Y. Example: (20 ÷ 100) × 200 = 40.
Mode 2: Percentage = (Part ÷ Whole) × 100. Example: (50 ÷ 200) × 100 = 25%.
Mode 3: Percentage change = ((To − From) ÷ From) × 100. Example: ((120 − 100) ÷ 100) × 100 = 20% Increase. If the new value is lower, the result is a Decrease.
Worked examples
Example 1: What is 20% of 200? Answer: 40.
Example 2: 50 is what percent of 200? Answer: 25%.
Example 3: What is the percentage change from 100 to 120? Answer: 20% Increase.
For a single increase or decrease on its own, try our Percentage Increase Calculator or Percentage Decrease Calculator. For a full comparison between two values, see the Percentage Change Calculator, and for sale prices, see the Percentage Discount Calculator.
Where percentages are used in daily life
Percentages are everywhere. In shopping, they show discounts and savings. When you eat out, they help you work out a tip. At school or university, they turn marks into grades. At work, they appear in tax, pay rises, interest rates and profit margins. Understanding percentages helps you compare prices, check bills and make smarter money decisions.
FAQs
What is a percentage?
A percentage is a number expressed as a fraction of 100. The symbol % means “per hundred”, so 25% is the same as 25 out of 100, or 0.25 as a decimal.
How do I work out a percentage of a number?
Divide the percentage by 100, then multiply by the number. For example, 20% of 200 is (20 ÷ 100) × 200 = 40.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, (50 ÷ 200) × 100 = 25%.
What is the difference between a percentage increase and a percentage decrease?
An increase means the new value is higher than the old value; a decrease means it is lower. Both are worked out with the same percentage-change formula, and the direction is shown by the words Increase or Decrease.
Can I use this calculator for discounts and tips?
Yes. Use Mode 1 to work out a discount amount or a tip, Mode 2 to check a mark or share as a percentage, and Mode 3 to compare an old price with a new price.
Disclaimer
This calculator provides estimated results based on the values entered and should be used for general information only. Always verify final figures with official sources before making financial decisions.