The gross rent multiplier (GRM) is a ratio used in real estate investment to compare the price of a property to its annual rental income before accounting for expenses such as property taxes, insurance, and utilities. It is calculated by dividing the fair market value of a property by its gross annual rental income. The GRM is a screening metric used by investors to compare rental property opportunities in a given market. A higher GRM indicates that the property is overpriced, while a lower GRM indicates that the property is underpriced. The GRM is a quick and easy way to determine the potential profitability of a real estate investment. However, it is important to note that the GRM is a blunt instrument in real estate analytics and is used primarily as an indicative screening tool rather than as a definitive indicator of value.