Percentage Calculator
This 3-in-1 percentage calculator answers the three most common percentage questions in one place. Enter Value A, Value B and a percentage to instantly get the result of applying that percentage to A, see what percent A is of B, and measure the percentage change from A to B. It is especially useful for grades, business reports, discounts, price changes, statistics and everyday math.
Frequently Asked Questions
To find X% of a number A, multiply A by X and divide by 100. For example, 15% of 200 = 200 × 15 / 100 = 30.
Percentage change from A to B = ((B − A) / |A|) × 100. A positive result means an increase; negative means a decrease. Example: from 200 to 500 → ((500−200)/200) × 100 = 150% increase.
This tells you what proportion A represents relative to B, expressed as a percentage. Formula: (A / B) × 100. Example: 200 out of 500 = (200/500) × 100 = 40%.
Percentage change measures how a value increased or decreased relative to its starting point. Percentage difference usually compares two values symmetrically. This calculator focuses on percentage change from A to B.
How this calculator works
Formula explanation
**Formulas:** X% of A = (X/100) × A | A is what % of B = (A/B) × 100 | % change A→B = ((B−A)/|A|) × 100
Worked example
**Example:** A = 200, B = 500, % = 15. → 15% of 200 = 30 | 200 is 40% of 500 | % change from 200 to 500 = +150%.
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