The standard gauge size for ear piercing is 20 or 18. The gauge size refers to the diameter of the piercing, and common sizes range from 20 through 00. A smaller number means a thicker diameter, and gauge sizes that are larger than 00 are expressed as fractions.
Ear piercings that utilize thick gauges may require a process that gradually stretches the earlobe holes, which typically uses surgical stainless steel rings or plugs. This method is preferred over piercing or punching large holes on the earlobes, which can make it difficult for the holes to return to a smaller diameter.