1. Measure your head size. To do this, pass a tape measure horizontally around your head at a height of about one inch above your eyebrows. When done properly, you will have measured the largest part of your head.
2. Check your measurement with the helmet sizing chart and select the closest size. As the helmet may not always meet your head size exactly, and your head measurement may fall between two sizes, first try the smaller size.
WHEN YOU RECEIVE YOUR HELMET
1. Expand the helmet opening by pulling outwards on each chinstrap, and slide your head into the helmet. If you are unfamiliar with helmets you may be reluctant to pull the helmet down, as it may feel too tight. Even if the helmet is difficult to put on, please use the smallest helmet possible. The helmet should feel snug. If the helmet is not tight, it is too big for you. New helmets will break in and loosen slightly over time.
2. Once the helmet is on:
Check that the helmet inner lining fits snugly all around your head.
Check that the top pad presses on the top of your head.
Check that the cheek pads press up against your cheeks. When you open and close your mouth, you should drag your teeth along the inside of your cheeks.
Check to make sure that you cannot easily slide your finger into the helmet along the side of your temple.
Hold the helmet with one hand on each side. Without moving your head, try to move the helmet up and down, and side to side. You should feel the skin of your head and face being pulled as you try to move the helmet. If you can move the helmet around easily, it is too big. Try a smaller size. Please note that during this check, the chinstraps should be properly fastened.