The gems and settings on nose rings start as small as 1.2 to 1.6mm – these sizes are known as micro nose rings. Gems and settings can go up to about 3mm in size. Decorative shapes can be even larger, sometimes measuring up to 6 or 7mm (about 1/4″) wide.
Also know, is a 16 gauge or 18 gauge nose ring bigger?
8 and 1 millimeters (18–gauge being vaguely thicker). People with petite noses can be pierced with a 22 gauge, which entails specialty jewelry. People with larger noses might consider going to a 16 gauge. Most nose jewelry will be available in 20- gauge since this size is predominately used just for nose piercings.