Measure how profitable an investment was. Enter the amount you invested and the amount it returned, and the calculator gives you the net profit and the return on investment as a percentage, using the standard formula (gain minus cost) divided by cost. Add the holding period in years and it also computes the annualized ROI, which converts the total return into an equivalent yearly rate so you can fairly compare investments held for different lengths of time. ROI is one of the clearest ways to judge whether something was worth it, from a stock or a property to a marketing spend or a side project. Enter your figures and the results appear instantly, computed entirely in your browser.