This study aimed to identify applicable sizing systems for big and tall men by examining current menswear sizing systems. A cluster analysis, a linear regression, and t-test with fit comparison plots were employed to test two dominant approaches of sizing systems: 1) a size chart based on proportions of a sampling distribution of means in normal distribution, which is the most common approach of sizing in the apparel industry; and 2) a size chart developed with a liner regression model. Body dimensions from a total of 301 big and tall men height over 71.5 inches and weight over 215 pounds were tested with the two size charts. Similar characteristics of big and tall were identified with the cluster analysis. While the sizing system with proportion displayed more deviations, the sizing system with a liner regression model predicted more of actual big and tall men’s body dimensions