Return on Investment (ROI) is a financial metric measuring the gain or loss generated relative to the amount invested. Expressed as a percentage, ROI helps evaluate whether investments are worthwhile by comparing returns to costs. While commonly used in business, governments also consider ROI when evaluating programs, infrastructure investments, and policy choices. For municipal investments, ROI analysis might assess whether a recreation centre generates sufficient community benefit relative to costs, or whether energy efficiency upgrades pay for themselves through reduced utility bills. Public sector ROI often includes non-financial benefits like community wellbeing, environmental improvement, or service quality alongside financial returns.