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Data / Number / Computer Science Tools

Percentage Calculator

Calculate percentages - X% of Y, percentage increase/decrease, percentage difference, and finding the original value before a change.

Choose the type of percentage calculation you need - each is clearly labeled with its own inputs and formula.

Percentage increase/decrease and percentage difference are calculated differently - increase/decrease is relative to the original value, while difference treats both values symmetrically.

Which Calculation Do You Need?

X% of Y finds a portion of a value. Percentage increase/decrease finds how much a value changed, relative to its original value. Percentage difference compares two values symmetrically (neither is treated as "original"). Find the original value works backward from a final value and a known percentage change.

How to Use It

  1. Choose the calculation type that matches what you need.
  2. Enter the relevant numbers.
  3. View the result along with the formula used.

Handling Division by Zero

Percentage change from zero is undefined (you can't express a change relative to nothing) - this tool clearly reports that case rather than showing an incorrect number like Infinity or NaN.

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