How to measure your face size

 
Guide: This model's face size is 20 (Regular)

 

 Face Size Face Opening (in inches)
19.5 (Petite) 19.5
20 (Regular) -- fits most 20
20.5 (Regular) -- fits most 20.5
21 (Plus) 21
21.5 (Plus) 21.5

Note: If you are unsure of your face size, choose 'Regular' (either 20 or 20.5) which fits most people.