About the Percentage Calculator
Percentages are everywhere: discounts, tips, taxes, exam scores, salary raises, interest rates and statistics. This calculator answers the four most common percentage questions at once, with results that update as you type. You can enter numbers with a dot or a comma as the decimal separator, and negative percentages work too, for example to apply a discount.
How to use it
- Find the calculator that matches your question.
- Enter your two numbers. The result appears instantly.
- Use a negative percentage in “Increase or decrease” to apply a reduction, such as -20 for a 20% discount.
- Copy the result with one click.
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 calculate percentage change?
Subtract the old value from the new value, divide by the old value and multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = +25%.
Why doesn't a 20% decrease followed by a 20% increase return to the original value?
Because the second percentage applies to a smaller number. 100 decreased by 20% is 80, and 80 increased by 20% is 96, not 100.