ROI calculator

ROI is (final value minus amount invested) divided by amount invested, so the same number can describe a two-week flip and a nine-year hold; only the annualized figure makes different holding periods comparable, and it compounds geometrically: (final over initial) to the power of one over years, minus one. The annualized figure is a rate per year, not a promise of the rate in any one year. This is arithmetic, not financial advice; it says nothing about risk, inflation, or what an alternative investment would have done.