// Free utility
Percentage Calculator
Discounts, increases, percentage changes between two numbers, VAT extraction and reverse percentage. Instant calculation in the browser, no upload.
For an already-applied discount use the minus sign (e.g. −20); for an already-applied increase use the positive value (e.g. 20).
Values are calculated locally in your browser — no data is sent to external servers.
How to calculate a percentage
To find out what 20% of 150 is, multiply 150 by 20 and divide by 100: the result is 30. To calculate a discount, apply the inverse formula instead: multiply the price by (1 minus the discount percentage divided by 100).
The percentage change between two numbers (useful for comparing prices, revenue, or any value that changes over time) is calculated by subtracting the initial value from the final one, dividing by the initial value, and multiplying by 100. A negative result indicates a decrease.
To find out what percentage a number represents of a total — for example what percentage "2 of 20000" or "75 of 1400" is — divide the value by the total and multiply by 100: use the "X is what % of Y" mode above by entering the two numbers.
To add or subtract multiple percentages on the same starting value (for example a 10% discount followed by a further 5%), calculate each step in sequence on the previous result: successive percentages don't simply add up, because each one applies to the new total.
To extract VAT from a total that already includes it, divide the total by (1 + rate/100): a total of €122 with 22% VAT corresponds to a taxable amount of €100 and a VAT share of €22. Use the "VAT extraction" mode above to do it automatically.
To work back to the original value starting from an amount already increased or discounted, divide the final value by (1 + percentage/100), using the minus sign for discounts: if a price discounted by 20% is €80, the original price was €100. The "Reverse percentage" mode handles the calculation automatically.
Frequently asked questions about percentage calculations
Multiply the original price by the discount percentage and divide by 100 to get the amount saved. For example, a 25% discount on €100 equals €25 saved, so the final price is €75. Alternatively, multiply the price directly by (1 − discount/100): 100 × 0.75 = 75 €. Use the "Discount" mode above for the instant result.
To increase a value by a certain percentage, multiply it by (1 + percentage/100). A 10% increase on €100 gives 100 × 1.10 = €110. For a 20% increase on €50: 50 × 1.20 = €60. The "Increase" mode shows both the final value and the increment in euros.
Divide the number by the total and multiply by 100. To find out what percentage 2 is of 20000, calculate (2 / 20000) × 100 = 0.01%. Likewise, 75 of 1400 corresponds to (75 / 1400) × 100 ≈ 5.36%. Enter the two values in "X is what % of Y" mode for an instant result.
Subtract the initial value from the final one, divide the difference by the initial value, and multiply by 100. Going from 100 to 120 is a change of ((120 − 100) / 100) × 100 = +20%. A negative result indicates a decrease: from 120 to 100 the change is −16.67%. The "% change" mode handles the sign automatically.
Sequential discounts don't add up: each one applies to the already-reduced price. A 10% discount followed by a further 5% on €100 gives first €90 (−10%), then €85.50 (−5% on 90), not €85. The real combined discount is therefore 14.5%, not 15%. Calculate each step in sequence, using the previous result as the new starting price.
All calculations happen locally in your browser via JavaScript. No value you enter is sent to external servers: the tool also works offline after the first load and is completely free, with no registration or usage limits.
Use the "VAT extraction" mode: enter the gross total (the price that already includes VAT) and the rate to extract. The formula is Net = Total / (1 + rate/100): with a total of €122 and 22% VAT, the taxable amount is €100 and the VAT share is €22.
Use "Reverse percentage" mode: enter the final value, after the increase or discount, and the percentage applied. The formula is Original = Final / (1 + percentage/100): for an increase enter the positive percentage, for an already-applied discount enter it with a minus sign. If a price discounted by 20% is €80, the original price was €100.