How to use the Percentage Calculator tool
- Find the line that matches your question.
- Type the two numbers.
- Read the result below the line.
The formulas
- X% of Y = Y × X ÷ 100. Example: 20% of 150 = 30.
- X is what % of Y = X ÷ Y × 100. Example: 30 is 25% of 120.
- Percentage change from A to B = (B − A) ÷ |A| × 100. Example: from 80 to 100 is +25%.
- Increase Y by X% = Y × (1 + X ÷ 100). Example: 250 + 15% = 287.5.
- Decrease Y by X% = Y × (1 − X ÷ 100). Example: 250 − 15% = 212.5.
Everyday examples
Discounts: a jacket costs 120 and is 30% off, so you pay 120 × 0.7 = 84. Tips: 15% of a 64 bill is 9.60. Salary: a raise from 3,000 to 3,240 is an 8% increase. VAT: adding 20% VAT to 500 gives 600.
Note that a percentage decrease followed by the same percentage increase does not bring you back: 100 minus 20% is 80, and 80 plus 20% is 96, not 100.
Privacy
Everything you type stays in your browser. Nothing is sent to a server or stored.
Frequently asked questions
How do I calculate a discount?
Use “Decrease Y by X%”: enter the price and the discount percent.
What is the difference between percent and percentage points?
If a rate goes from 10% to 12%, it rose by 2 percentage points, which is a 20 percent increase.
How do I reverse a percentage?
To find the original price before a 20% increase, divide by 1.2. For example, 120 ÷ 1.2 = 100.
Can I use decimals and negative numbers?
Yes. All fields accept decimals and negative values.