The size 1X typically corresponds to a plus size 14/16, and it is designed to fit more roomier and is actually fit for plus size individuals. It follows the 1X to 3X shape and is based on the body fit of usual plus size sizing and products. The 1X size is part of a unique sizing system specifically engineered to be the best fit, feel, and look for plus size individuals. In American sizes, an XL is generally considered to be a 14-16, and a 1X is typically a 16-18, with some overlap between the two sizes.