Percentage Calculator
Percentages, VAT and discounts
Percentage Calculator: Quick Discounts, Interest and Statistics
Percentages are everywhere: sale discounts, VAT/taxes, tips, compound interest, statistics, price increases. Our calculator covers 4 essential operations: what X% of Y is, what percentage X is of Y, percentage change, and reverse calculation (find the original before discount).
Everything runs in your browser without external dependencies. Includes step-by-step formulas so you understand how the result is derived — useful for students, freelancers invoicing, and anyone dealing with finances.
Precision to 2 decimals by default (adjustable). No ads, no telemetry, no history saved: private math.
How does it work?
- 1Select the operation
Choose between: X% of Y, X is what % of Y, % change from A to B, or price before discount.
- 2Enter the values
Fill in the required fields. Decimals accepted with dot or comma.
- 3See the result
You'll get the numerical result and the formula used to arrive at it.
Frequently Asked Questions
Discounted price = Original price × (1 - discount%/100). Example: 100 with 20% discount = 100 × 0.80 = 80. Our calculator does it automatically.
Price + VAT = Price × (1 + VAT%/100). Example: 100 + 21% VAT = 100 × 1.21 = 121. To go backwards: base price = price with VAT ÷ (1 + VAT%/100).
Simple interest applies to the original principal each period. Compound applies to the accumulated principal (interest generates more interest). For long periods, compound interest generates much more return.