How to find your size
1. Get a tape measure and a mirror.
2. Take the tape measure and place it at the nape of your neck; then bring it forward on both sides, passing slightly above your ears, above your eyebrows, and roughly at the center of your forehead. When doing this, make sure the tape is not too tight.
3. Read the measurement you obtained in the mirror and compare it with the table to determine your size.
4. A tip: if you don't have a tape measure, you can use a small ribbon or string instead and then check the measurement on a rigid measuring tape.