Jewelry is measured through a gauge system (see chart below).

 

The *higher* the gauge number the *smaller* the wire is.

A standard "earring" is usually 20 gauge.

A standard ear piercing at an actual shop with a needle is usually a 14 gauge.

To get larger gauge piercings you have to stretch your piercings.

 

Jewelry gauges/sizes can vary between manufacturers.

There is no universal regulation on companies to make a standard size in body jewelry.

A big part of this is that some jewelry is made overseas and measured in millimeters.

And in the USA jewelry is measured in inches/gauges.

So many times jewelry can be anywhere from .5mm to 1mm different.

 

Gauge Millimeter Inch
16g 1.2mm 3/64"
14g 1.6mm 1/16"
12g 2mm 5/64"
10g 2.4mm 3/32"
8g 3.2mm 1/8"
6g 4mm 5/32"
4g 5mm 3/16"
2g 6mm 1/4"
0g 8mm 5/16"
00g 9mm to 10mm 3/8"
  11mm 7/16"
  13mm 1/2"
  14mm 9/16"
  16mm 5/8"
  19mm 3/4"
  22mm 7/8"
  25mm 1"
  26.9mm 1-1/16"
  28.5mm 1-1/8"
  30.1mm 1-3/16"
  31.7mm 1-1/4"
  33.3mm 1-5/16"
  34.9mm 1-3/8"
  36.5mm 1-7/16"
  38.1mm 1-1/2"
  39.6mm 1-9/16"
  41.2mm 1-5/8"
  44.4mm 1-3/4"
  47.6mm 1-7/8"
  51mm 2"