Percentage Calculator
Calculate percentages, ratios, and change rates instantly with three calculation modes.
Result
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How to Use the Percentage Calculator
This free percentage calculator handles the three most common percentage problems. Simply select the mode that matches your question, enter the values, and click Calculate.
Calculation Modes
- X% of A — Finds a percentage of a number. Example: 20% of 500 = 100
- A is what % of B? — Finds what percent A is of B. Example: 25 is 12.5% of 200
- % Change — Finds the percentage increase or decrease between two values. Example: 80 → 100 is a 25% increase
Formulas
- X% of A = A × X ÷ 100
- A is what % of B = A ÷ B × 100
- % Change = (New − Old) ÷ Old × 100
Common Uses
- Calculate tip amounts at restaurants
- Work out VAT or sales tax
- Find exam scores as percentages
- Track sales growth or decline
- Calculate commission amounts
Frequently Asked Questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 20% of 500 = 500 × 20 ÷ 100 = 100. Use the "X% of A" mode and enter 500 and 20.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100. For example, 25 is what percent of 200? 25 ÷ 200 × 100 = 12.5%. Use the "A is what % of B" mode.
How do I calculate percentage change?
Percentage change = (New − Old) ÷ Old × 100. If a price goes from 80 to 100, the change is (100 − 80) ÷ 80 × 100 = 25% increase.
Can I use this for discount calculations?
Yes, for simple percentage discounts. For full discount calculations including the discounted price, use the Discount Calculator.
Is the calculator free?
Yes, completely free. No account or download required.