For Jacket and Lame: Measure your chest circumference (right below the armpits) in inches, add two and round up to the nearest even number, that will be your jacket and lame size.
For pants: Measure your waist, round up to the nearest even number, that will be your pants size.
For gloves: measure your hand circumference, right at the knuckles, in inches, round up to the closest number.
For mask: To find your mask size, measure your head circumference with a flexible tape measure. Start under your chin, go up the side of your head, over one ear, across the top, down the other ear, and back under your chin. Measure snugly to ensure a proper fit. Choose a larger size if you are between sizes. Sizes are: XS under 21" (53 cm), S 21"-23" (53-59 cm), M 24"-25.5" (60-65 cm), L 26"-28" (66-71 cm), XL over 28" (over 71 cm).
For plastron: sizes are based on height for both men and women. Choose Extra Small if under 5', Small for 5'1"–5'3", Medium for 5'4"–5'6", and Large for 5'7"–5'11".
