Four types of percentage calculations — instant results
| Calculation | Formula | Example |
|---|---|---|
| X% of Y | (X ÷ 100) × Y | 20% of 500 = 100 |
| X is what % of Y | (X ÷ Y) × 100 | 25 is 12.5% of 200 |
| % Change | ((New − Old) ÷ Old) × 100 | 100 to 125 = +25% |
| Original value | Final ÷ (1 + Change%/100) | 80 after −20% = 100 |