How is percentage change calculated?

(new - old) / |old| x 100. Going from 80 to 100 is a 25% increase; going from 100 to 80 is a 20% decrease.

Is anything I enter stored?

No. The calculation happens in your browser and nothing is sent or saved.

JavaScript is turned off. InspireTools processes files in your browser, so the tools need JavaScript to run.

Find a percentage of a number, percentage change, and reverse percentages.