Standard cowl sizes vary based on personal preference, but the following is a good rule of thumb: - Snug Fitting Cowl: 22" - 23" circumference x 8" - 14" H (depending how slouchy you'd like it). - Loose Fitting Cowl: 30" circumference x 8" - 14" H. - Infinity Scarf: 60" circumference x 6" - 8" H.