roi

ROI is an acronym used in several domains, most commonly to denote return on investment, region of interest, or the Republic of Ireland. The meaning depends on context and field.

Return on investment (ROI) is a financial metric used to assess the profitability of an investment. It is calculated by dividing the net gain from the investment by its cost and expressing the result as a percentage: ROI = (Net Profit / Cost of Investment) × 100. ROI is widely used to compare projects, campaigns, or assets; however, it has limitations, such as ignoring the time value of money and risk, and it can be distorted by accounting choices.

Region of interest (ROI) refers to a defined subset of a data set or image selected for analysis. In medical imaging, an ROI might be drawn around a lesion to quantify its size or intensity. In computer vision and image processing, ROI pooling and ROI-based detection focus computation on relevant image regions to improve efficiency and accuracy.

Republic of Ireland is sometimes abbreviated ROI in historical or organizational contexts, though the ISO country code is IRL and the internet domain is .ie. The use of ROI as a geographic acronym is less common in modern standard usage and can vary by organization or publication.