Percentage Calculator

About This Tool

The Percentage Calculator solves the three most common percentage problems in one tool: finding a percentage of a number, finding what percentage one number is of another, and calculating the percentage change between two values.

All calculations run instantly in your browser. No data is sent to any server. Results are rounded to two decimal places for practical use.

How to Use

1. Select the calculation mode: X% of Y, X is what % of Y, or % Change.
2. Enter the required numbers in the input fields.
3. The result updates instantly as you type.

Formulas Explained

X% of Y: result = (X ÷ 100) × Y. Example: 20% of 150 = 30. X is what % of Y: result = (X ÷ Y) × 100. Example: 30 is 20% of 150. % Change: result = ((New − Old) ÷ Old) × 100. Positive = increase; negative = decrease. Example: from 80 to 100 is a 25% increase.

Use Cases

Shoppers calculate sale prices and discount amounts while shopping. Students calculate their exam score as a percentage of total marks. Business analysts track month-over-month revenue growth. Marketers calculate conversion rates and ad click-through rates. Investors compute portfolio return percentages and dividend yields.

FAQ

• What is the difference between percentage and percentage points? — Percentage point is the arithmetic difference (5% → 8% = 3 percentage points); percentage change is relative (5% → 8% = 60% increase).
• How do I calculate a discount? — Use "X% of Y": enter the discount rate as X and the original price as Y to find the discount amount. Subtract from the original for the sale price.
• What is a percentage increase vs decrease? — Use the % Change mode. A positive result is an increase; a negative result is a decrease (e.g., −10 means a 10% decrease).