Jewelry & Materials
Body Jewelry Sizing Guide: Gauge, Length, and Fit by Piercing
How body jewelry is sized, with a gauge-to-mm-and-inch chart, how each jewelry shape is measured, and the common gauge and length for every piercing type.
Body jewelry is sized by gauge (its thickness) and by length or diameter, and the right numbers depend on the piercing. This guide covers gauge sizes with a millimeter and inch conversion chart, how each jewelry type is measured, and the sizes commonly used for each piercing, whether you are buying for yourself or as a gift.
If you already know the piercing you are shopping for, jump to a dedicated guide:
- Nose ring sizes, gauge and diameter for nostril studs and hoops
- Septum jewelry sizing, gauge, diameter, and styles
- Threaded vs threadless jewelry, how the ends attach
- Implant-grade titanium jewelry, the metal that heals well
- Ear stretching and gauges, going to a larger size safely
Gauge sizes
Gauge is the thickness of the jewelry, on a numbered scale where a bigger number means thinner metal. A 20g post is thinner than a 14g one, which trips people up the first time. Here is a conversion chart for common gauge sizes to millimeters and fractional inches.
Gauge conversion chart
| Gauge (g) | Millimeters (mm) | Inches (approx) |
|---|---|---|
| 22g | 0.6mm | 0.024” |
| 20g | 0.8mm | 0.032” |
| 18g | 1.0mm | 0.039” |
| 16g | 1.2mm | 0.047” |
| 14g | 1.6mm | 0.063” |
| 12g | 2.0mm | 0.079” |
| 10g | 2.4mm | 0.094” |
| 8g | 3.2mm | 0.126” |
| 6g | 4.0mm | 0.157” |
| 4g | 5.0mm | 0.197” |
| 2g | 6.0mm | 0.236” |
| 0g | 8.0mm | 0.315” |
Millimeters are the number to trust, since gauge readings drift slightly between manufacturers. Going to a larger gauge than you were pierced at means stretching the piercing gradually over time, one size at a step, not forcing a thicker bar through the channel. Our ear stretching guide covers how that is done without tearing tissue.
Measuring jewelry
Each jewelry shape is measured a different way, so a “10 mm” ring and a “10 mm” barbell describe different distances.
| Jewelry type | How it is measured |
|---|---|
| Ring or hoop | Inner diameter, from inside edge to inside edge |
| Straight barbell | Length between the inside of the two ball ends, threads excluded |
| Curved barbell | Length in a straight line between the inside of the two ends |
| Labret stud | Post length from the flat disc base to the ball, threads excluded |
| Clicker | Diameter for hoops, length for a straight or curved section |
For studs and barbells the number that matters is the wearable length, the part of the post that sits in and through the piercing. For anything circular, it is the inner diameter.
Threaded vs threadless
The ends attach to the post in one of two ways. Threaded ends screw onto a threaded post and hold securely, though externally threaded posts drag a rough screw thread through the channel on the way in. Threadless ends use a slightly bent pin that presses into a hollow post, so nothing rough passes through the piercing and changes are quicker.
For a healing piercing, internally threaded or threadless jewelry is the safer choice, because neither pulls a thread through fresh tissue. The threaded vs threadless guide breaks down the difference in detail.
Sizes by piercing type
Each piercing has a common gauge and a typical length or diameter range. Use this table to shortlist a size, then read the notes below for the piercings where anatomy and swelling change the math.
| Piercing | Common gauge | Typical length or diameter | Common jewelry |
|---|---|---|---|
| Earlobe | 18g to 16g | 6 to 8 mm | Flat-back studs, hoops, dangles |
| Cartilage (helix, tragus, conch) | 16g | 6 to 10 mm | Flat-back studs, small hoops, labret studs |
| Eyebrow | 16g to 14g | 8 to 10 mm | Curved barbells, rings |
| Nostril | 20g to 18g | 6.5 to 8 mm post, 8 mm hoop | Nose studs (bone, L-bend, screw), hoops |
| Septum | 16g to 14g | 8 mm diameter (6 to 10 mm) | Circular barbells, captive bead rings, clickers |
| Lip and labret | 16g to 14g | 8 to 10 mm | Labret studs, rings |
| Tongue | 14g | 16 to 19 mm fresh, shorter once healed | Straight barbells |
| Navel | 14g | 10 mm (some 11 to 12 mm) | Curved barbells, dangles |
| Nipple | 14g | 12 to 16 mm | Straight or curved barbells, rings |
Fresh piercings on the tongue, navel, and nipple start on a longer bar to leave room for swelling, then downsize once it settles. Downsizing means swapping to a shorter post, which a piercer usually does a few weeks in. A tongue often drops from a 16 to 19 mm starter bar to around 14 mm after healing.
Nipple gauge is 14g for most people, with 12g sometimes used for larger anatomy, and the length varies enough that measuring beats guessing. Nostril and septum jewelry differ more than their shared “nose” label suggests: the nostril sits thinner at 20g to 18g, the septum thicker at 16g to 14g. The nose ring and septum guides carry full length and diameter breakdowns for each.
Whatever the size, a fresh piercing heals best in a smooth, biocompatible metal. Implant-grade titanium (ASTM F-136) is the safe default, and our titanium jewelry guide explains why “surgical steel” is a looser term than it sounds.
Buying jewelry as a gift
Body jewelry makes a personal gift, but sizing and taste make it easy to miss. Read the person’s gauge, metal, and style from what they already wear. Neutral metals and simple shapes are the safest guess when you are unsure. If you know the studio that pierced them, ask their piercer for the gauge and length on file. Include a gift receipt so they can exchange a size that does not fit. When you cannot pin down the numbers, a gift card lets them pick the exact size and piece themselves.
Before you buy
Confirm two numbers before you order anything: the gauge you were pierced at and the length or diameter that fits your anatomy. Match the gauge exactly, since a thicker bar tears a healing channel and a thinner one leaves the jewelry loose. If you have a piece that already fits, measure it with a caliper or take it to your studio rather than guessing. For the two piercings that trip people up most, the nose ring and septum sizing guides go deeper than any single chart can.
Frequently asked
How is body jewelry gauge measured?
Gauge is the thickness of the post or wire, on a numbered scale where a bigger number means thinner metal. A 20 gauge post (0.8 mm) is thinner than a 14 gauge one (1.6 mm). The scale runs backward because it carried over from wire manufacturing. Millimeters are the reliable measurement, since gauge numbers vary slightly between makers.
What gauge is standard for a navel piercing?
14 gauge (1.6 mm) is the standard for a navel piercing, almost always as a curved barbell. A fresh navel usually starts on a longer bar, around 10 mm, to leave room for swelling, then downsizes to a shorter bar once the swelling settles.
How do I measure barbell length?
Measure the straight line between the inside of one ball end and the inside of the other, not counting the balls or threads. For a ring or hoop you measure the inner diameter instead, straight across the inside of the circle. A digital caliper gives the most accurate reading.
What size is a standard nose ring?
Most nostril piercings use 20 gauge (0.8 mm) or 18 gauge (1.0 mm) jewelry, and nostril hoops most often measure 8 mm across the inside. Septum piercings sit thicker, usually 16g or 14g, at an 8 mm diameter.
Can I wear a different gauge than my piercing?
Match the gauge you were pierced at. Forcing a thicker bar through a healing channel tears tissue, and a thinner one leaves the jewelry loose and prone to catching. Going to a larger gauge means stretching the piercing gradually over time, not swapping in a bigger bar.