Percentage Calculator
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What this calculator does
This percentage calculator solves the five most common percentage questions without any formulas to remember. Choose what you want to work out, type two numbers and the answer appears straight away. It is useful for discounts, grades, tax, salary raises, statistics and everyday maths.
How to use it
- Pick a calculation from the list.
- Fill in the two boxes that appear.
- Read the result and, where relevant, the difference.
The five calculations
- X% of a number: result = X ÷ 100 × number.
- X is what % of Y: result = X ÷ Y × 100.
- % change from X to Y: result = (Y − X) ÷ |X| × 100. A negative answer means a decrease.
- Add X% to a number: result = number × (1 + X ÷ 100).
- Subtract X% from a number: result = number × (1 − X ÷ 100).
Example: adding 14% VAT to 100 gives 100 × 1.14 = 114, and the difference shown is 14. A price falling from 200 to 150 is a change of −25%.
Tips
Results are rounded to four decimal places. You can type numbers with Arabic-Indic digits (٠-٩), a decimal comma or a decimal point. Percentage change cannot be calculated from zero, and you cannot divide by zero, so the tool will tell you if the numbers do not allow it. Everything is calculated in your browser.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100. For example, 50 is 50 ÷ 200 × 100 = 25% of 200.
How is percentage change calculated?
Subtract the old value from the new one, divide by the old value and multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = 25% increase.
Why does adding 20% and then subtracting 20% not return the original number?
The second percentage is taken from a different, larger number. Adding 20% to 100 gives 120, and 20% of 120 is 24, so subtracting it leaves 96.