Percentage Calculator

Find a percentage of a number, express one number as a percentage of another, or calculate percentage change.

Result
30
Result
20%
Change
+25%

Formulas used

  • X% of Y = (X ÷ 100) × Y
  • X is what % of Y = (X ÷ Y) × 100
  • Change = ((Y − X) ÷ X) × 100

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Three ways to think about percentages

Most real-world percentage questions fall into one of three shapes: finding a share of a number, expressing one number as a share of another, or measuring how much something has grown or shrunk. This calculator covers all three at once, so you don't need to remember which formula to rearrange.

How do I calculate a discount?

Use the first box: X is the discount percentage, Y is the original price. Subtract the result from Y to get the sale price.

Why is percentage change negative sometimes?

A negative result means the "to" value is lower than the "from" value — a decrease rather than an increase.