The mask is the one piece you must size right, and you never buy it big. Measure around your head just above the ears and eyebrows, enter it below, and get the typical size. Then confirm on the brand chart and try it on at your club.
| Head circumference | Typical mask size |
|---|---|
| Under 54 cm (21 in) | Child / extra-small |
| 54 to 56 cm (21 to 22 in) | Small |
| 57 to 59 cm (22.5 to 23 in) | Medium |
| 60 cm (23.5 in) and up | Large |