Arai Sizing Information

How to size
ARAI Helmets
Size Head Circumference (in) Head Circumference (cm) Hat Size
X-SMALL 20 7/8 - 21 1/4 53-54 6 5/8 - 6 3/4
SMALL 21 5/8 - 22 55-56 6 7/8 - 7
MEDIUM 22 3/8 - 22 3/4 57-58 7 1/8 - 7 1/4
LARGE 23 1/8 - 23 1/2 59-60 7 3/8 - 7 1/2
X-LARGE 24 - 24 3/8 61-62 7 5/8 - 7 3/4
XX-LARGE 24 3/4 - 25 1/8 63-64 7 7/8 - 8
 
ARAI OPTIONAL/REPLACEMENT LINER THICKNESS GUIDE
HELMET SIZE LINING CODE 12MM THICKNESS 10MM THICKNESS 7MM THICKNESS 5MM THICKNESS
X-SMALL II (SM) OPTIONAL OPTIONAL STANDARD OPTIONAL
SMALL II (SM) OPTIONAL OPTIONAL STANDARD OPTIONAL
MEDIUM III (MD) OPTIONAL STANDARD OPTIONAL OPTIONAL
LARGE III (MD) OPTIONAL OPTIONAL STANDARD OPTIONAL
X-LARGE IV (LG) OPTIONAL OPTIONAL STANDARD OPTIONAL
XX-LARGE IV (LG) OPTIONAL OPTIONAL OPTIONAL STANDARD
 
ARAI OPTIONAL/REPLACEMENT CHEEKPAD THICKNESS GUIDE
HELMET SIZE CORSAIR V RX-Q VECTOR-2 SIGNET Q VX-PRO 3 XD4
OPTIONAL 40MM - - 40MM 35MM 35MM
OPTIONAL 35MM 35MM - 35MM - -
X-SMALL (STANDARD) 30MM 30MM 30MM 30MM 25MM 25MM
SMALL (STANDARD) 30MM 30MM 30MM 30MM 25MM 25MM
MEDIUM (STANDARD) 30MM 30MM 30MM 30MM 25MM 25MM
LARGE (STANDARD) 25MM 25MM 25MM 25MM 20MM 20MM
X-LARGE (STANDARD) 25MM 25MM 25MM 25MM 20MM 20MM
XX-LARGE (STANDARD) 25MM 25MM 25MM 20MM 20MM 20MM
OPTIONAL 15MM - - 15MM 12MM 12MM
OPTIONAL 12MM - - 12MM - -
SHELL INTERIOR SHAPE* I/O I/O I/O L/O I/O I/O
*I/O - Intermediate Oval - more info
*L/O - Long Oval - more info