Percentage Change Calculator

Calculate percentage increase or decrease between two values. Also computes percentage of a number and reverse percentage.

Updated April 2026 · CalcFlow Editorial

Enter values above and click Calculate to see your results.

What is a Percentage Change? Percentage change measures how much a value has increased or decreased relative to its original value, expressed as a percentage. It is one of the most common calculations in finance, retail, and data analysis.

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Rule of Thumb

A positive percentage change is an increase; negative is a decrease. Percentage change from 100 to 200 is +100%, but from 200 to 100 is -50% — the starting value matters.

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Example Calculation

A price that rose from $80 to $100 increased by ($100 - $80) / $80 x 100 = 25%. A salary cut from $50,000 to $45,000 is a decrease of ($45,000 - $50,000) / $50,000 x 100 = -10%.

Key Facts

  • Percentage change and percentage point change are different: a rate going from 4% to 6% is a 2 percentage point increase but a 50% relative increase.
  • Percentage change is symmetric only in theory — a 50% drop requires a 100% gain to recover.
  • In finance, a 10% loss followed by a 10% gain does NOT return to the original value.

How to Use

  1. Select what you want to calculate from the dropdown.
  2. For Percentage Change: enter the original value and the new value.
  3. For Percentage OF: enter the total (field 1) and the percentage (field 2).
  4. For Reverse: enter the result (field 1) and the known percentage (field 2).
  5. Click Calculate to see the result.

Formula

Percentage Change = ((New - Old) / |Old|) x 100 | X% of Y = (Y x X) / 100 | Reverse: Original = Value / (Percent / 100)
FromToPercentage ChangeNotes
100110+10%10% increase
10090-10%10% decrease
50100+100%Doubled
10050-50%Halved
10001200+20%Common raise scenario
200150-25%Sale / discount scenario
0.51.0+100%Decimal values work

Frequently Asked Questions