Percentage Calculator

Percentages express a proportion as a fraction of 100. The symbol % means 'per hundred' — so 50% is 50 per 100, or one half. Percentages are used everywhere: discounts, taxes, tips, interest rates, statistics, and growth metrics.

The four core percentage operations are: finding what X% of a number is, finding what percent X is of Y, calculating percentage change between two values, and applying a percentage increase or decrease to a value. This calculator handles all four with instant results.

What is X% of Y? → (Y × X) / 100. X is what % of Y? → (X / Y) × 100. Percent change from X to Y? → ((Y - X) / X) × 100. X increased by Y%? → X × (1 + Y/100). X decreased by Y%? → X × (1 - Y/100).

These formulas are the building blocks of financial calculations, data analysis, and everyday math. Memorizing them or having a quick reference (like this tool) speeds up calculations significantly.

Percentages are essential in business: profit margins (profit / revenue × 100), markup (selling price / cost - 1) × 100, tax calculations, discount pricing, and year-over-year growth. Sales teams use percentage change to track performance. Finance uses percentages for interest rates, APY, and investment returns.

When comparing values of different magnitudes, percentages normalize the data. A $10 increase on a $50 item (20%) is very different from a $10 increase on a $500 item (2%), even though the dollar change is the same.

The tip/discount section provides a fast way to calculate gratuity or sale prices. Enter the bill amount and tip percentage to see the tip amount and total. The same logic applies to discounts: enter the original price and discount percentage to get the discounted price and amount saved.

Common tip percentages: 15% (standard), 18% (good service), 20% (excellent). For discounts, 10% off, 25% off, and 50% off are frequent. This tool gives instant results for any percentage you choose.