The Real Estate Asset Climate Testing (REACT) tool is designed to estimate the risk (in euro/year) for individual assets making use of a simplified risk calculation. The goal of the tool is to offer simple, open, and transparent insights for real estate managers and policymakers to assess different types of flood risks (coastal, riverine, pluvial) for their assets. The tool should be used by data analysts who have some Geographic Information System (GIS) knowledge, though no extensive GIS or flood knowledge is required. There is a basic calculation where a generic estimate of the value of an asset is used, whereas the advanced calculation allows for a more detailed approach where the user can specify the value of the asset, and, when applicable, include the elevation of the asset above surface level, presence of floodproofing measures, and changes in flood probability due to climate change. The Excel file contains the tool and the technical documentation provides background information and guidelines on the Real Estate Asset Climate Testing (REACT) tool for flood risk assessments.