Percentage Change Calculator: Formula & Worked Example

Measure increase or decrease from an old value to a new value. Calculate instantly in your browser with editable inputs, a worked example and clear assumptions. No account required.

How it is calculated

(New value − Old value) ÷ Old value × 100

The old value must be nonzero. Negative starting values change how the percentage should be interpreted.

Worked example

Old value

100

New value

120

Example result: 20.00%

The interactive tool lets you edit every input and reset to this example. Calculations run in your browser.

Questions and answers

Are my calculator inputs sent to a server?

These calculations run in your browser. The calculator does not send your entered values to a calculation server or save them to your learning account.

Why can the result differ from a full spreadsheet model?

Each calculator uses the equation and assumptions shown on this page. Displayed values may be rounded. A workbook with different timing, fees, filters or source data can produce a different result.

Can I use the calculator without an account?

Yes. All 73 calculators are available to guest learners. The worked example shows the default inputs, and Reset restores them.

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• Profit Margin — Calculate profit as a percentage of selling price.

All 73 calculators · Practise in the Excel Simulator

Interactive practice runs in your browser.