Percentage Calculator

About the Percentage

This percentage calculator handles the everyday percentage problems that come up constantly in shopping, finance, cooking, and data analysis — percentage of a number, percentage change, and reverse percentages. Percentages are everywhere: discounts, tips, interest rates, taxes, markups, grade scores, and statistical changes, so being able to do them correctly saves you money and avoids error. The three most common operations are covered. To find what percent one number is of another, divide the part by the whole and multiply by 100 — 30 is 15% of 200. To find a percentage of a number, multiply the number by the percentage as a decimal — 15% of 200 is 30. To work out percentage change between two values, subtract the old from the new, divide by the old, and multiply by 100 — a price that rises from £50 to £60 is a 20% increase. Enter the two numbers you have and the calculator works out the result and shows the working, so you can see exactly how it got there. This matters because percentages can mislead when the base changes. A 50% discount followed by a 50% markup does not bring you back to the original price — because the markup is computed on the already-discounted price, the final price is only 75% of the original. Similarly, a stock that falls 50% then rises 50% only recovers to 75% of its original value. Use this calculator for discounts while shopping, for checking a price rise, for working out tips and taxes, for grading and statistics, and for financial analysis. When a politician or headline says "a 20% increase in cost," this tool quickly shows what that means in real numbers. Accurate percentages protect your money and your decisions.