Change & growth

Percentage Change Calculator

Measure how much a value increased or decreased relative to where it started. Results update instantly as you type.

Live calculation
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Private by design

Your numbers are calculated in this browser. No account or database is required.

How this calculator works

Percentage change = (new − old) ÷ |old| × 100

Percentage change is directional: the original value is the baseline, so swapping the old and new values usually produces a different percentage.

PercentScope also shows the absolute difference and a visual old-versus-new comparison so you can interpret the result without doing extra math.

Example: 120 to 165

The increase is 45. Dividing 45 by the original 120 gives 0.375, so the percentage change is a 37.5% increase.

Frequently asked questions

What if the original value is zero?

A standard percentage change is undefined when the original value is zero because the formula would divide by zero.

Is percentage change the same as percentage difference?

No. Percentage change uses the original value as the baseline; percentage difference compares two values symmetrically using their average.