Determining flesh hoop size can be easily calculated. Subtracting the skin thickness from the outside diameter of the head accurately yields the size of the flesh hoop inside the skin. It’s important to note that the skin thickness is multiplied by two [outside diameter of head – (skin thickness x 2) = flesh hoop size]. Let’s say we have a head with an outside diameter of 12-1/4″ and a 1/16″ skin. A 1.6mm skin is roughly 1/16″ thick. So we have 1/8″ of skin. 12-1/4″ – (1/16″ x 2) = 12-1/8″