U.S. standard clothing size
HistoryWomen''s SizesConversion from Catalog SizesStandardsSee AlsoReferencesMen''s standard sizes were probably developed first during the American Revolutionary War, and they were in regular use by the American army during the War of 1812 for ready-made uniforms.These were based on the chest measurement, with other measurements being assumed to be either proportional (the circumference of the neck, waist, hips, and thighs)...See more on en.wikipedia Proper Cloth
Standard Sizes, Types of Fit, and Size Charts - Proper
Find your perfect fit at Proper Cloth: understand the different types of fit and sizes available for custom dress shirts and casual shirts.