Free Chrome extension · Now on the Chrome Web Store
Our free piercing gauge converter tells you how thick 14G is in millimeters, or which gauge is closest to a 3 mm bar, in one click. The Piercing Gauge & Jewelry Size Converter is a Chrome extension from Desire Surgical that sits in your browser toolbar. It converts gauges to millimeters and inches, finds the nearest listed gauge for any millimeter size, and converts jewelry lengths and ring diameters between inches and millimeters. It works offline, needs no account and collects no data.
What the piercing gauge converter does
- Gauge to millimeters and inches: pick any gauge from 20G to 00G and see its rounded nominal diameter in millimeters, plus the equivalent in inches. Every result notes that real jewelry varies by manufacturer, with an extra note for large gauges.
- Millimeters to the closest gauge: enter a diameter and see the matching gauge when it equals a nominal reference size. Otherwise you see the closest listed gauge, clearly labeled as approximate, with the exact difference in millimeters.
- Exact inch and millimeter conversion: convert decimals, fractions such as 5/16″ and mixed numbers such as 1 1/4″ using 1 inch = 25.4 mm. Quick presets cover common bar lengths and ring inner diameters in inch and metric sizes.
- Searchable gauge size chart: every listed gauge with nominal millimeters, inches and to-scale comparison circles. Search by gauge or by millimeters.
- Copy in one click: copy a clean result such as “14G ≈ 1.6 mm nominal diameter” into an order, a quote or a message to a customer.
- Private and offline: no permissions, no tracking and no network requests. Light and dark mode, and full keyboard support.
Piercing gauge chart: gauge to mm and inches
| Gauge | Nominal mm | Inches (from mm) |
|---|---|---|
| 20G | 0.8 mm | 0.031 in |
| 18G | 1.0 mm | 0.039 in |
| 16G | 1.2 mm | 0.047 in |
| 14G | 1.6 mm | 0.063 in |
| 12G | 2.0 mm | 0.079 in |
| 10G | 2.5 mm | 0.098 in |
| 8G | 3.2 mm | 0.126 in |
| 6G | 4.0 mm | 0.157 in |
| 4G | 5.0 mm | 0.197 in |
| 2G | 6.0 mm | 0.236 in |
| 0G | 8.0 mm | 0.315 in |
| 00G | 9.0 mm | 0.354 in |
These are rounded nominal values based on the Association of Professional Piercers’ historical conversion reference. Actual dimensions vary by jewelry manufacturer, so check the manufacturer’s specification when precision matters.
Common jewelry sizes in inches and millimeters
Gauge is only the thickness of the jewelry. Bar length and ring inner diameter are separate measurements, usually sold in fractions of an inch. These convert exactly at 1 inch = 25.4 mm, and the converter’s in / mm tab handles any other size.
| Inches | Millimeters | Often used for |
|---|---|---|
| 1/4″ | 6.35 mm | Short bars, small ring inner diameters |
| 5/16″ | 7.94 mm | Bar lengths and ring inner diameters |
| 3/8″ | 9.53 mm | Bar lengths and ring inner diameters |
| 7/16″ | 11.11 mm | Bar lengths and ring inner diameters |
| 1/2″ | 12.7 mm | Bar lengths and ring inner diameters |
| 9/16″ | 14.29 mm | Longer bars |
| 5/8″ | 15.88 mm | Longer bars, larger rings |
| 3/4″ | 19.05 mm | Longer bars, larger rings |
A full jewelry size combines both, for example a 16G ring with a 3/8″ (9.53 mm) inner diameter.
How to use the gauge converter extension
- Install the extension from the Chrome Web Store and click Add to Chrome.
- Pin it: click the puzzle-piece icon in Chrome’s toolbar, then the pin next to “Piercing Gauge & Jewelry Size Converter”.
- Open it by clicking the icon.
- Choose a tab: Gauge to mm, mm to Gauge, in / mm, Chart or Guide.
- Select or type a value. The result updates instantly.
- Click Copy Result to copy it to your clipboard.
Privacy and permissions
The extension requests no Chrome permissions, makes no network requests and collects no personal or usage data. The only thing it remembers is your light or dark theme choice, stored on your own device. Read the full extension privacy policy.
Piercing gauge converter FAQ
How many millimeters is 14G?
14G is approximately 1.6 mm (0.063 in). This is a rounded nominal value, and actual jewelry can measure slightly differently depending on the manufacturer.
What gauge is 1 mm?
1.0 mm corresponds to 18G as a nominal reference value. The next sizes are 20G at 0.8 mm (thinner) and 16G at 1.2 mm (thicker).
What is 00G in mm?
00G is listed as approximately 9 mm in this chart. Large gauges vary more than small ones, and some suppliers list 00G anywhere from about 9 mm to 10 mm, so always confirm the manufacturer's stated size.
Is the Piercing Gauge Converter free?
Yes. The extension is free, with no account, subscription or ads.
Does it work offline?
Yes. All sizes and calculations are built into the extension, so it works without an internet connection.
Why does a smaller gauge number mean thicker jewelry?
The gauge system comes from wire making, where each pass through a smaller drawing die made the wire thinner and raised its number. That is why 14G is thicker than 18G, and why sizes beyond 0G continue as 00G.
Are the millimeter values exact?
They are rounded nominal reference values. Manufacturers use slightly different dimensions, especially for large gauges such as 00G, which suppliers list at anywhere from about 9 mm to 10 mm. When precision matters, check the manufacturer’s specification and measure the jewelry.
What is the difference between gauge, length and inner diameter?
Gauge is the thickness of the jewelry. Length is how long a bar is between its ends. Inner diameter is the distance across the inside of a ring. A full jewelry size usually needs the gauge plus a length or an inner diameter.
Why does the mm lookup say “approximate”?
If your value does not equal a listed nominal size, the extension shows the closest gauge and the difference in millimeters instead of claiming an exact match.
Does it give piercing or medical advice?
No. It is a measurement reference only. Consult a qualified professional piercer for anything related to an individual piercing.
Support and feedback
Found a problem or want a size added? Contact us or message us on WhatsApp and mention “Gauge Converter”.
Professional piercing instruments
Desire Surgical makes body piercing instruments for studios and suppliers in its own Sialkot workshop, including piercing tool kits, ring opening pliers, ring closing pliers and Pennington forceps. Browse the catalogues or request a wholesale quote.