About Size Size 21in = Approx. 57cm in length, suitable for 21-inch ukulele.(Soprano) Size 23 / 24in = Approx. 65cm in length, suitable for 23/24 inch ukulele.(Concert) Size 26in = Approx. 69cm in length, suitable for the 26-inch ukulele.(Tenor) If you are unsure of the size of your ukulele, we recommend that you measure your ukulele first. The ukulele bag must be longer than your ukulele. Please note this!