The most common gauge for a helix piercing is 16 gauge, although some are done at 14 gauge instead. If you did not go to a piercer to have it professionally done, and instead had your ear pierced anywhere that uses a piercing gun, then the gauge you wear may be smaller than the standard size. For example, it isn’t uncommon to find someone that wears 20 gauge or 18 gauge jewelry in their upper cartilage piercing because they had it done at the mall. Its important to know what gauge you were pierced with when replacing any piercing. The standard lengths for helix piercings are 3/16”, 1/4”, 5/16”, and 4/8” .
In summary, the most common gauge for a helix piercing is 16 gauge, but its important to know what gauge you were pierced with when replacing any piercing.