Gauges run backwards — a bigger number is a thinner bar. Pick a gauge and see it in millimetres and inches, drawn at its real size on your own screen, or measure a bar you already own, or start from the piercing and get the gauge and length shops stock for it.
16g · 4 of 13 on the scale
0.05 in (1.2 mm)The thickness of the bar, not its length.
Piercings normally done at this gauge
If you are stretching
Gauge charts from Body Candy and Urban Body Jewelry; per-piercing sizes from Body Candy and BodyJewelry.com; stretching guidance quoted from the Association of Professional Piercers. Checked 2026-09-20. The AWG column is computed from the standard’s own formula.
Quick answer: gauges run backwards — a bigger number is a thinner bar. The common ones are 20g = 0.81 mm, 18g = 1.0 mm, 16g = 1.2 mm, 14g = 1.6 mm and 12g = 2.0 mm. Earlobes and nostrils are usually 20g or 18g, cartilage and lips 16g, navels, nipples and tongues 14g. The scale stops at 00g; above that, sizes are fractions of an inch.
How to use it
Choose A gauge and the chart gives you that thickness in millimetres and inches and draws it at its real size on your screen. Choose A measurement if you already own the bar and can measure it — or hold it against the ruler under the answer. Choose A piercing and you get the gauge it is normally done at, plus the stud length or hoop diameter shops stock for it.
Before you trust the drawing, open Set the scale for your screen once and drag the box until it is exactly the size of a bank card. Every card in the world is 85.6 mm wide (ISO/IEC 7810 ID-1), so it is the one ruler everybody already owns. The setting is saved in your browser and you will never be asked again.
The thing nobody tells you: a gauge is not exactly a gauge
Body-jewellery gauges are named after American Wire Gauge, whose diameters come from one formula: 0.127 × 92(36 − n) ÷ 39 millimetres. But shops do not sell those numbers — they round to convenient metric sizes. 16g is sold as 1.2 mm; 16 AWG is 1.291 mm. That is 7% thinner than the scale it is named after.
The Association of Professional Piercers quotes the true AWG steps: it says the jump from 14g to 12g is “.43mm” and from 4g to 2g “1.36mm”. The AWG gaps are 0.42 mm and 1.36 mm — a hundredth away at most. On the metric labels the same jumps are 0.4 mm and 1.0 mm. Neither side is lying; they are two roundings of one wire gauge, and the table below prints both so you can see which one you are holding.
It gets one layer stranger. Body Candy’s own chart lists 16g as 1.2 mm and as 0.050 inches — and 0.050 inches is 1.27 mm. One row of one chart, two numbers 6% apart. Buy by the millimetre a shop prints, not by converting its inches.
Every gauge, three ways
“Sold as” is what shops print and what you should order by — Body Candy and Urban Body Jewelry print the same millimetres, checked on 2026-09-20. “True AWG” is computed from the standard’s formula. The last column is how far apart they are.
| Gauge | Sold as | True AWG | Inches | Drift |
|---|---|---|---|---|
| 22g | 0.64 mm | 0.644 mm | 0.025 in | -0.6% |
| 20g | 0.81 mm | 0.812 mm | 0.032 in | -0.2% |
| 18g | 1 mm | 1.024 mm | 0.04 in (5/128) | -2.3% |
| 16g | 1.2 mm | 1.291 mm | 0.05 in (3/64) | -7.0% |
| 14g | 1.6 mm | 1.628 mm | 0.064 in (1/16) | -1.7% |
| 12g | 2 mm | 2.053 mm | 0.081 in (5/64) | -2.6% |
| 10g | 2.4 mm | 2.588 mm | 0.102 in (3/32) | -7.3% |
| 8g | 3.2 mm | 3.264 mm | 0.125 in (1/8) | -2.0% |
| 6g | 4 mm | 4.115 mm | 0.162 in (5/32) | -2.8% |
| 4g | 5 mm | 5.189 mm | 0.204 in (3/16) | -3.6% |
| 2g | 6 mm | 6.544 mm | 0.25 in (1/4) | -8.3% |
| 0g | 8 mm | 8.251 mm | 0.312 in (5/16) | -3.0% |
| 00g | 10 mm | 9.266 mm | 0.375 in (3/8) | +7.9% |
Two rows are worth a second look. 16g and 10g are about 7% thinner than the gauge scale says, and 00g is about 8% thicker — the only size where the sold bar is bigger than its own gauge. That matters if you are stretching: on the ladder shops sell, 0g → 00g is a 2.0 mm jump, while on the gauge scale itself it is about 1.0 mm. The APP’s rule is to “avoid” stretching more than one full gauge at a time — by its own numbers, that one step is nearly two.
Above 00g, it is inches
The Association of Professional Piercers puts it plainly: jewellery thickness is measured “by gauge (rather than millimeters), and above a certain size (00 gauge), by fractions of an inch”. This is the ladder every shop uses from there.
| Millimetres | Inches |
|---|---|
| 11 mm | 7/16 in |
| 12 mm | 1/2 in |
| 14 mm | 9/16 in |
| 16 mm | 5/8 in |
| 19 mm | 3/4 in |
| 22 mm | 7/8 in |
| 25 mm | 1 in |
| 28 mm | 1 1/8 in |
| 32 mm | 1 1/4 in |
| 35 mm | 1 3/8 in |
| 38 mm | 1 1/2 in |
| 41 mm | 1 5/8 in |
| 44 mm | 1 3/4 in |
| 47 mm | 1 7/8 in |
| 51 mm | 2 in |
What each piercing is normally done at
Standard sizes, not rules. Your piercer chose for your anatomy, and a fresh piercing is fitted longer than a healed one so there is room to swell — it gets downsized once the swelling goes.
| Piercing | Usual gauge | Usual length or diameter |
|---|---|---|
| Earlobe | 20g or 18g | stud 6 mm (1/4 in) or 8 mm (5/16 in) · hoop 8 mm (5/16 in) to 12 mm (1/2 in) |
| Helix / cartilage | 16g | stud 8 mm (5/16 in) · hoop 6 mm (1/4 in) to 10 mm (3/8 in) |
| Tragus | 16g | stud 6 mm (1/4 in) or 8 mm (5/16 in) · hoop 6 mm (1/4 in) to 10 mm (3/8 in) |
| Daith | 16g | hoop 6 mm (1/4 in) to 10 mm (3/8 in) |
| Conch | 16g | stud 8 mm (5/16 in) · hoop 6 mm (1/4 in) to 10 mm (3/8 in) |
| Rook | 16g | hoop 6 mm (1/4 in) to 10 mm (3/8 in) |
| Industrial | 14g | bar 32 mm (1 1/4 in) or 38 mm (1 1/2 in) |
| Nostril | 20g or 18g | stud 6 mm (1/4 in) or 8 mm (5/16 in) · hoop 6 mm (1/4 in) to 8 mm (5/16 in) |
| Septum | 16g | hoop 8 mm (5/16 in) to 10 mm (3/8 in) |
| Eyebrow | 16g | bar 8 mm (5/16 in) |
| Labret / lip | 16g | stud 8 mm (5/16 in) or 10 mm (3/8 in) |
| Tongue | 14g | bar 16 mm (5/8 in) |
| Navel | 14g | bar 10 mm (3/8 in) |
| Nipple | 14g | bar 12 mm (1/2 in) or 14 mm (9/16 in) |
Sources: Body Candy’s size chart by piercing and BodyJewelry.com, both checked on 2026-09-20. Where they differ the tool shows both rather than averaging them: BodyJewelry.com lists labrets at 16g or 14g and its lengths run 6–12 mm against Body Candy’s 8 or 10 mm.
Three worked examples
“My helix jewellery keeps falling out.” Helix is normally 16g (1.2 mm) with an 8 mm post. If you bought an earlobe stud it is probably 20g (0.81 mm) and 6 mm — thinner than the hole and shorter than the cartilage, which is exactly how a stud works its way loose.
“The bar measures 1.4 mm.” That is between 16g (1.2 mm) and 14g (1.6 mm), and a bar has to fit through the hole you have, so the safe answer is the thinner one — 16g. If it genuinely will not go in, it is a 14g hole and your calipers are reading the ball.
“I’m at 0g and want 00g.” Measure first. Sold 0g is 8 mm and sold 00g is 10 mm — a 2 mm step, where a single gauge is normally about 1 mm. Half sizes exist for exactly this; the APP recommends them “particularly in larger size jumps”.
Common mistakes
- Reading the scale forwards. 20g is thinner than 14g. If a bar feels too thick, you want a bigger number.
- Measuring the ball. The gauge is the bar. Decorative ends are always wider.
- Converting the inches. A chart’s own inch column often comes from AWG while its millimetre column is a rounded trade size. Order by millimetres.
- Confusing gauge with length. Gauge is how thick; length (a straight bar) or inner diameter (a hoop) is how big. A “16g 8 mm” is one of each.
- Buying a healed size for a fresh piercing. New piercings are fitted long on purpose. Downsizing is a separate appointment, not a mistake by the piercer.
- Stretching on a schedule instead of on the tissue. The APP says a piercing “should never bleed or appear torn when stretched”, and that recovery between sizes “can take anywhere from several weeks to months or even longer”.
More on Needle Style
Ear piercing ideas, nose piercing ideas, belly button piercing ideas, hoop earrings, stud earrings and this year’s earring trends.
This is a size chart, not medical advice. It does not diagnose anything, and a piercing that is hot, swollen, painful or leaking needs a piercer or a doctor, not a bigger bar. Stretching guidance is quoted from the Association of Professional Piercers, checked 2026-09-20.
FAQ
What gauge are most earrings?
Standard earlobe piercings are made at 20g (0.81 mm) or 18g (1.0 mm), and most fashion earrings are made to fit them. Cartilage — helix, tragus, conch, daith, rook — is normally 16g (1.2 mm), which is why an ordinary lobe stud is too thin and too short for it.
Is a bigger gauge number thicker or thinner?
Thinner. The numbers count down as the bar gets thicker: 20g, 18g, 16g, 14g, 12g, 10g and so on, then 0g and 00g. There is no 00 followed by another zero on this scale — above 00g, sizes are written as fractions of an inch.
What is 16g in mm?
1.2 mm as shops sell it. The true 16 AWG diameter is 1.291 mm, and the same charts often print 0.050 inches for it, which is 1.27 mm. All three are in the table above; order by the millimetre figure.
What size nose ring do I need?
Nostrils are normally pierced at 20g (0.81 mm) or 18g (1.0 mm). For a hoop, the inner diameter that usually fits is 6 to 8 mm; for a stud or screw, 6 or 8 mm of post. Septums are thicker — 16g (1.2 mm) — with an 8 to 10 mm hoop.
How do I measure my own jewellery?
Measure the bar, not the ball. With calipers, close them on the plain part of the post. Without, set your screen scale above and hold the bar against the ruler under the answer — a millimetre is easy to see once the ruler is life size. Then switch to A measurement and type what you read.
What length barbell do I need?
It depends on the piercing, not the gauge. Cartilage studs are usually 8 mm, navels 10 mm, nipples 12 or 14 mm, tongues about 16 mm once healed, and industrials 32 to 38 mm. Hoops are measured by inner diameter instead: 6 to 10 mm for most cartilage, 8 to 12 mm for a lobe.
How many gauges can I stretch at once?
One, at most. The Association of Professional Piercers says stretching more than one full gauge size “should be avoided” and that half sizes should be used “particularly in larger size jumps”. Watch the 0g to 00g step especially: on the sizes shops sell it is a 2 mm jump, roughly two gauges’ worth.
Why is my new jewellery too long?
Because it is supposed to be. A fresh piercing is fitted with a longer bar so there is room for swelling; once that settles, a shorter one is fitted. If a healed piercing is still wearing its original long bar, the extra movement is what catches on clothes and irritates it.