Percentage Calculator for Beginners
Here is a beginner-friendly table covering all essential percentage concepts:
| Concept | Explanation | Example |
|---|---|---|
| Definition of Percentage | A percentage is a number expressed as a fraction of 100. | 50% = 50/100 = 0.5 |
| Converting Fraction to Percentage | Multiply the fraction by 100. | 3/4 × 100 = 75% |
| Converting Decimal to Percentage | Multiply the decimal by 100 and add a % sign. | 0.25 × 100 = 25% |
| Converting Percentage to Decimal | Divide the percentage by 100. | 75% ÷ 100 = 0.75 |
| Finding Percentage of a Number | Multiply the number by the percentage (as a decimal). | 20% of 50 = 0.2 × 50 = 10 |
| Percentage Increase | Increase = (New Value – Old Value) ÷ Old Value × 100 | (120 – 100) ÷ 100 × 100 = 20% |
| Percentage Decrease | Decrease = (Old Value – New Value) ÷ Old Value × 100 | (100 – 80) ÷ 100 × 100 = 20% |
| Finding What Percent One Number is of Another | (Part ÷ Whole) × 100 | (30 ÷ 200) × 100 = 15% |
| Discount Calculation | Discount = (Discount % × Original Price) | 20% off $100 = 20/100 × 100 = $20 |
| Increase by a Percentage | New Value = Original + (Percentage × Original) | Increase $50 by 10% = 50 + (10% of 50) = $55 |
| Decrease by a Percentage | New Value = Original – (Percentage × Original) | Decrease $50 by 10% = 50 – (10% of 50) = $45 |
| Percentage Points vs Percent Change | Percentage points refer to the difference between two percentages, while percent change measures relative change. | From 10% to 15% is a 5 percentage point increase, but a 50% relative increase. |