ROI Calculator — Free Online Tool

The ROI Calculator expresses the return on an investment as a percentage of what was put in, dividing net gain by cost, and also shows annualised return so investments held for different lengths of time can be compared.

Annualising is the part that makes ROI meaningful rather than misleading. A 50 percent return sounds excellent until you learn it took eight years, at which point it is roughly 5 percent a year — worse than many far safer options. Raw ROI ignores time entirely, so comparing two investments on raw ROI alone systematically favours whichever was held longer. Any comparison between opportunities needs the annualised figure.

Two costs routinely get left out and both flatter the result. Transaction and holding costs — fees, commissions, platform charges, maintenance, tax — come out of the return and often account for a meaningful share of it. And opportunity cost: capital committed to one thing could have been earning elsewhere, so the honest comparison for a marketing spend or a project is against the next best use of the money, not against zero.

For marketing specifically, attribution is the harder problem than the arithmetic. Calculating ROI on a campaign requires knowing which revenue the campaign actually caused rather than which revenue happened afterwards, and those are different questions that most reporting quietly conflates.

Calculation happens in your browser; no figures are transmitted.

Our ROI Calculator is completely free to use with no signup required. For this tool, processing runs in your browser — your files and data stay on your device and are not uploaded to our servers.

Whether you are a developer, designer, student, or business owner, this tool is designed to save you time and make your workflow more efficient. Bookmark this page to access it whenever you need it — it will always be free.