Piercing Gauge to MM Conversion: The Complete Sizing Guide
What Is a Gauge?
In body jewelry, "gauge" refers to the thickness of the jewelry post or wire — but here's the confusing part: a higher gauge number means a thinner piece of jewelry. So a 20G nose ring is thinner than a 14G belly ring. Understanding this helps you order the right fit every time.
Gauge to MM Conversion Chart
| Gauge | Millimeters (mm) | Inches | Common Piercing Types |
|---|---|---|---|
| 20G | 0.81 mm | 1/32" | Nose, upper ear cartilage |
| 18G | 1.0 mm | 5/128" | Nose, ear lobe, cartilage, septum |
| 16G | 1.2 mm | 3/64" | Eyebrow, daith, rook, tragus, lip |
| 14G | 1.6 mm | 1/16" | Belly button, nipple, tongue, septum |
| 12G | 2.0 mm | 5/64" | Stretched ears, industrial |
| 10G | 2.4 mm | 3/32" | Stretched lobes |
| 8G | 3.2 mm | 1/8" | Stretched lobes |
What Gauge Is Standard for Common Piercings?
- Septum rings: 16G or 14G — explore our Septum Rings
- Belly rings: 14G is the most common standard — browse our Belly Piercings collection
- Nostril: 20G or 18G
- Helix / cartilage: 16G
- Ear lobes: 20G or 18G (standard piercing gun size)
How to Measure Your Jewelry Diameter
Diameter refers to the interior width of a ring (hoop) or the length of a straight bar. Common sizes:
- Rings/Hoops: 6mm, 8mm, 10mm — measured across the inside of the circle
- Belly bars: Typically 10mm length
- Septum clickers: Usually 8mm–10mm inner diameter
For a full reference, visit our Size Guide and printable Size Conversion Chart.
Tips for Getting the Right Fit
- When in doubt, go with the standard gauge for your piercing type — your piercer used it for a reason.
- Don't size up too fast if stretching ears. Move up only one gauge at a time and give 4–6 weeks between sizes.
- Measure before you buy. If you have an existing piece of jewelry you love, use digital calipers to measure the post thickness before ordering a replacement.
- Contact us if you're unsure — we're happy to help you find the right fit.