There is no hard rule for mask sizing. Most males with a good sized head wear the large; most females medium. That being said, If you are a male with a particularly narrow or small head, the medium may be a better choice. Same goes for females with large skulls; you may want a large. For more specific measurements, check out our Mask Sizing Chart.
Ensuring a good fit is the most important aspect of any mask.
It must seal to filter the air passing through to your lungs otherwise you are wasting
your money or just looking cool with Respro® – we want you to do both; the
classic ‘Win Win’ scenario.
As a rule of thumb mask sizing is as follows:
a. 5’ Light Build = Small
b. 5’ Heavy Build – 5’6’ Average Build = Medium
c. 5’6” Heavy Build – 6’ Average Build = Large
d. 6’ Heavy Build – 6’+ Average Build = X-Large