By using the data from 15 countries in Asia, this study aims to improve the current global flood risk assessment methods in the aspects of vulnerability proxy selection and a risk calculation formula. In estimating global flood risk, the current methods treat vulnerability in a very simplistic manner. Based on recent literature and empirical findings, this study classifies vulnerability into susceptibility (in terms of marginalized groups, unplanned urbanization, and weak governance), and coping capacity. Each of the four components is, in light of global data availability, expressed by eight proxies, namely, age-related dependency ratio, undernourishment prevalence, urbanization growth rate, deforestation, corruption perceptions index, and three core scores from the Hyogo Framework for Action. Regarding the risk calculation formula, this study tries to break through the limitations of the multiple regression, which is commonly used for estimating coefficients and parameters, by applying the partial least squares regression (PLSR) method. The PLSR method makes it possible to include many proxies in the formula without lowering the explanatory power, even when the proxies are highly correlated.