To get the best result from My Swim Cap in terms of protecting your hair from chlorine and salt water, select the size that completely covers your ears. In addition, your hair should completely fill the cap with no extra space. Note: Even if you have a snug fit, if you can push/squeeze down on the top of the cap and feel air pushing out, you need a smaller size. For dry hair, it is better that you are stretching the cap to fit (as the cap is made to stretch) than having any room/air in the cap. You should use a tape measure to measure around your hairline (over the ears), then use the pictures and descriptions in the Sizing Guide to determine which size will work best for you. Importantly, My Swim Cap is made of neoprene so, like a wetsuit, if it is snug initially, please know it will stretch and give (for a customized fit) after a couple hours wear.
UNISEX: Head Circumference less than 22 inches, Non-Voluminous Hair
UNISEX PLUS: Head Circumference 22 inches or greater or Voluminous Hair
DIVA PLUS: Head Circumference 22 inches or greater, Substantial Hair, Braids, Twists, Locs and Extensions
JUNIOR: For Kids
Diva Plus (for long, thick, voluminous hair, braids and extensions): The Diva Plus has substantial room in the cap for the placement of long, thick, voluminous hair, braids, locs or extensions. The Diva Plus has a hairline circumference of 20 inches (which is stretchable up to 24 inches).
Unisex Plus (for thick shoulder-length hair or long, straight hair): The Unisex Plus has a bit more room than the Unisex for the wearer whose hair is too voluminous for the Unisex, but does not fill the Diva Plus. The Unisex Plus is best for thick shoulder-length hair, as well as long, straight hair. Unisex Plus may also be appropriate for short hair if your head is larger than average size (i.e. larger than 22 inches when measuring around the hairline (over the ears)). The Unisex Plus has a hairline circumference of 19 inches (which is stretchable up to 24 inches).
Unisex (for short to shoulder length hair): The Unisex is shaped like traditional swimming caps. The Unisex has a hairline circumference of 18 inches (which is stretchable up to 22 inches).
Junior (for kids): The Junior is specially sized for small kids, and is shaped like traditional swimming caps. The Junior has a hairline circumference of 18 inches (which is stretchable up to 21 inches). Moreover, the crown of the Junior is smaller than the crown of the Unisex. Generally speaking, the Junior is too small for teenagers, adults and children with long hair or braids.