ROI Calculator

Return on investment (ROI) answers the most basic question any investor asks: how much did I actually make, relative to what I put in? This calculator takes an initial investment amount, the investment's final value, and how long it was held, and instantly works out two different, and both useful, answers: the total return over the whole period, and the annualized return you'd need to compound at every year to get the same result.

Total ROI is the simpler of the two: (Final Value − Initial Investment) ÷ Initial Investment × 100. It tells you the overall percentage gain or loss over the entire holding period, with no regard for how long that period was: a 50% total ROI means the same thing whether it took 6 months or 6 years.

Annualized return (CAGR, compound annual growth rate) answers a different, often more useful question: what steady, compounding annual rate would have produced this same total return? The formula is ((Final Value ÷ Initial Investment) ^ (1 ÷ Years) − 1) × 100. This is what actually lets you compare two investments held for different lengths of time on equal footing: a 50% total ROI over 5 years is a much weaker result (roughly 8.4% a year) than the same 50% total ROI over 1 year, even though the total-return figure alone looks identical.

Both figures update live as you type, with no "Calculate" button to press, and the holding period accepts fractional years (like 0.5 for six months or 2.5 for two and a half years) for exact partial-year periods. A negative final value relative to the initial investment is handled the same way as a gain: both figures simply come out negative, correctly reflecting a loss. Every calculation runs as plain JavaScript directly in your browser, so nothing you type is ever sent to a server, logged, or stored anywhere.