Earring Gauge Size Chart: mm and Inch Conversions Explained
Jewellery gauge (written as a number plus "g") describes the thickness of the post or wire that passes through a piercing. The system runs backwards from what most people expect: a higher gauge number means a thinner post. A standard lobe stud is usually 20g or 18g (roughly 0.8–1.0 mm), most cartilage jewellery is 16g (about 1.2 mm), and stretched piercings move down the scale towards 0g and beyond. The earring gauge chart below converts every common size to millimetres and inches, then explains how to measure a post before ordering.
Earring gauge chart: 22g to 00g
Body-jewellery gauges are inherited from wire-gauge conventions rather than from a metric standard, which is why the conversions look uneven (the numbering system is described under American wire gauge). The millimetre values below are the rounded figures most spec sheets use.
| Gauge | Millimetres (approx.) | Inches (approx.) | Commonly used for |
|---|---|---|---|
| 22g | 0.6 mm | 0.025" | Thin nose studs, some fashion earrings |
| 20g | 0.8 mm | 0.032" | Standard stud earrings, nose studs |
| 18g | 1.0 mm | 0.040" | Lobe studs, nose rings, some helix jewellery |
| 16g | 1.2 mm | 3/64" | Cartilage, helix, septum, eyebrow |
| 14g | 1.6 mm | 1/16" | Navel, tongue, industrial, nipple |
| 12g | 2.0 mm | 5/64" | Stretched lobes, some body piercings |
| 10g | 2.4 mm | 3/32" | Stretched lobes |
| 8g | 3.2 mm | 1/8" | Stretched lobes |
| 6g | 4.0 mm | 5/32" | Stretched lobes |
| 4g | 5.0 mm | 3/16" | Stretched lobes |
| 2g | 6.0 mm | 1/4" | Stretched lobes |
| 0g | 8.0 mm | 5/16" | Stretched lobes |
| 00g | 10.0 mm | 3/8" | Stretched lobes |
Two details are worth memorising. First, the scale is inverted: 16g is thicker than 18g. Second, after 0g the sizing switches to 00g and then usually to plain millimetre measurements, because the wire-gauge system was never designed to go that large.
Typical gauges by piercing
Piercing studios vary in their defaults, and healed piercings can tighten around thinner jewellery over time, so the sizes below are common starting points rather than rules (an overview of piercing practice is available under body piercing).
- Ear lobe: pierced at 20g or 18g in most studios; nearly all fashion studs fit.
- Helix and other cartilage: usually 16g, sometimes 18g.
- Nose: 20g or 18g depending on region and studio.
- Septum, eyebrow, lip: commonly 16g.
- Tongue, navel, nipple: commonly 14g.
How to measure a post at home
Measure the jewellery, not the piercing. The reliable tools are a digital caliper (measure the post diameter away from any threading) or a printed gauge card with punched holes. If neither is available, compare the post against another earring whose gauge is known. Reading a seller's listing is usually faster: reputable product pages state the post diameter in millimetres, and that number matters more than the gauge label, because rounding differs between sellers.
When sizing up or down, change one step at a time. Jumping a healed lobe from 18g straight to 14g stresses the tissue, and downsizing works the same way in reverse: a channel that has stretched around 14g jewellery will feel loose with a 20g stud but usually shrinks back gradually if thinner jewellery is worn consistently. Piercers generally recommend waiting until a piercing is fully healed before changing gauge at all.
Gauge, length and material are three separate specs
Gauge only describes thickness. Post length (commonly 6, 8 or 10 mm for studs) decides comfort on thicker lobes, and the material decides how skin reacts. For sensitive ears the material usually matters more than the thickness — 316 stainless steel, often sold as surgical steel, is a widely used low-nickel-release option (background under surgical stainless steel). A well-written spec therefore reads like "18g (1.0 mm) × 8 mm post, 316 stainless steel" — three independent facts.
How to verify gauge when buying wholesale
Bulk buyers get burned by gauge more often than retail shoppers, because a batch that arrives 0.2 mm thicker than the last restock will not fit customers' healed piercings. Before committing to a larger order, ask the supplier to state the post diameter in millimetres on the quote (not just "18g"), confirm the tolerance they work to, and order a sample to measure with calipers. Keeping the measured value on file makes every future restock checkable against the same number.
For ready-stock 316 pieces in standard 20g–16g sizes, browse stud earrings, or send sizes and quantities through the wholesale page to get availability confirmed per SKU.
FAQ: earring gauge sizes
What gauge is a normal earring?
Most standard lobe studs are 20g (0.8 mm) or 18g (1.0 mm). If an earring fits a freshly pierced lobe from a typical studio, it is almost certainly in that range.
Is 16g bigger than 18g?
Yes. Gauge numbers run backwards: 16g (about 1.2 mm) is thicker than 18g (about 1.0 mm). The smaller the number, the thicker the post.
What gauge is a nose piercing?
Commonly 20g or 18g, with 20g more usual in North America and 18g in many other regions. A studio can confirm the size used at piercing time.
Can an 18g earring go into a 16g piercing?
Usually yes, since the post is thinner than the channel, but a healed 16g piercing may slowly tighten around 18g jewellery. Going the other way — forcing thicker jewellery into a smaller channel — risks tearing and should be done only as gradual, properly spaced stretching.