Here is a size conversion chart to help you with your body jewelry sizes 

 

Size Conversion Chart

Gauge

 

Length & Diameter

Gauge

Millimeters

 

Inches

Millimeters

00 ga

10.00mm

 

 

 

0 ga

8.0mm

 

5/64

2mm

2 ga

7.0mm

 

5/32

4mm

3 ga

6.0mm

 

1/4

6mm

4 ga

5.0mm

 

5/16

8mm

6 ga

4.0mm

 

3/8

10mm

8 ga

3.2mm

 

1/2

12mm

10 ga

2.5mm

 

9/16

14mm

12 ga

2.0mm

 

5/8

16mm

14 ga

1.6mm

 

11/16

18mm

16 ga

1.2mm

 

3/4

20mm

18 ga

1.0mm

 

7/8

22mm

20 ga

0.8mm

 

15/16

24mm

 

The gauge of body jewellery is the thickness of the steel.

The size of rings is usually the internal diameter and the outer diameter for tunnels and tubes etc.