Quick Answer
20 gauge is 0.8 mm thick, and it is the thinnest size commonly sold for nostril jewelry. If a listing says 20G and nothing else, it has told you the post thickness and nothing about whether the piece will fit you. Three numbers decide that: the gauge (0.8 mm), the diameter for a hoop or the wearable length for a stud, and the size of the visible end. 20G suits healed nostril piercings that were pierced and healed at that size. It is thinner than 18G (1.0 mm) and 16G (1.2 mm), so it is not a substitute for a larger size, and it is not something to change into on a fresh piercing without a piercer deciding.
Key Takeaways
- 20 gauge means 0.8 mm. A lower number is thicker, so 18G and 16G are both thicker than 20G.
- Gauge is thickness only. Diameter (hoops) and wearable length (studs) are separate numbers and are never implied by the gauge.
- 20G is the common nostril size for healed piercings and for jewellery that reads as subtle.
- A 20G piece in a piercing healed at 18G sits loose; an 18G piece forced into a 20G hole is a stretch, not a swap.
- If a piercing is fresh, swollen, painful, embedding, or uncertain, the size and the timing are a professional piercer’s call.
What 20 gauge actually measures
Gauge is a wire-thickness scale, and it runs backwards: the bigger the number, the thinner the metal. 20G is 0.8 mm. 18G is 1.0 mm. 16G is 1.2 mm. That 0.2 mm step between 20G and 18G looks trivial on paper and feels obvious in a nostril, because the difference is being felt against a hole that has already healed to a fixed size.
The scale itself comes from American Wire Gauge, which specifies nominal wire diameters rather than jewellery. Applying it to body jewellery is a convention the industry shares, not a regulated requirement, which is why the millimetre value on a listing matters more than the gauge number in the title. Two listings can both say 20G and still differ in how the piece is finished, how long the post is, and how large the end is.
For nostril jewellery specifically, 20G and 18G cover most of what is sold. 20G reads finer and is the size most people picture when they think of a small nose stud. 18G holds slightly more metal and is a common choice where a piercer wants a bit more substance at the exit point.
Gauge, diameter and wearable length are three different numbers
This is where most ordering mistakes happen. A listing can state 20G correctly and still be the wrong piece, because gauge says nothing about the two dimensions that decide fit.
| Measurement | What it describes | Where it applies | Typical nostril values |
|---|---|---|---|
| Gauge | Thickness of the metal | All jewellery | 20G (0.8 mm), 18G (1.0 mm), 16G (1.2 mm) |
| Diameter | Inner width of the circle | Hoops and rings | 6 mm, 8 mm, 5/16″, 3/8″ |
| Wearable length | Straight distance between the ends | Studs, bones, L-bends, barbells | 1/4″, 5/16″, 6 mm, 8 mm |
| End size | Width of the visible top | Studs and gem ends | 1.5 mm to 4 mm |
| Rise | How far the piece stands off the skin | Surface-style and some studs | Varies by construction |
A 20G hoop with a 6 mm diameter and a 20G hoop with a 10 mm diameter are the same thickness and completely different pieces of jewellery. The first hugs the nostril; the second hangs below it. Both are correctly described as 20 gauge.
20G vs 18G vs 16G on a nostril
| 20G | 18G | 16G | |
|---|---|---|---|
| Thickness | 0.8 mm | 1.0 mm | 1.2 mm |
| Visual weight | Finest, most subtle | Slightly more present | Noticeably more metal |
| Common use | Healed nostril, small studs and fine hoops | Healed nostril, standard studs | Nostril where a piercer wants more substance; other placements |
| Changing between sizes | Going from 18G to 20G leaves a loose fit | Going from 20G to 18G is a stretch | Not a swap from 20G |
| Availability | Very wide | Very wide | Wider outside nostril than inside |
The practical rule: stay at the size the piercing healed at unless a piercer has told you otherwise. Moving down a size is not neutral. A 20G post in an 18G hole can migrate and can let the hole tighten unevenly around a thinner post. Moving up a size is a stretch and takes time and assessment, not a purchase decision.
How to tell what your piercing already wears
Three ways, in order of reliability.
- Measure the piece you already wear. A cheap digital caliper on the post gives the thickness in millimetres; 0.8 mm is 20G, 1.0 mm is 18G, 1.2 mm is 16G. Measure the post, not the decorative end.
- Read the original listing or ask the studio. If the piercing was done at a studio, the size is in their record. This is the only method that tells you what the piercing was healed at rather than what happens to be in it now.
- Compare against known jewellery. If you have a 20G piece and an 18G piece, the difference is visible side by side even without a caliper.
What does not work: judging by how the jewellery looks in a photo, or assuming that a piece bought as “nose ring” is a particular gauge. Listings frequently omit the gauge entirely, and a photo cannot show 0.2 mm.
What 20G is right for, and what it is not
20G is a good fit when the piercing is fully healed, was healed at 20G, and the goal is a subtle look: a fine hoop, a small gem stud, a low-profile retainer for situations where metal is best kept discreet.
It is not the right size when:
- The piercing was done and healed at 18G or 16G. A 20G piece will sit loose and can migrate.
- The piercing is fresh, still healing, swollen, or has been irritated recently. Changing jewellery during healing is a decision for a piercer who can see the tissue.
- The jewellery needs to carry weight, such as a dangle or a chain. Thin metal plus hanging mass is a poor combination at the nostril.
- The hole has enlarged over time, which happens. A thinner post in a larger hole is not a fix.
Fit problems worth catching before you order
A post that is too short. Wearable length decides whether the piece sits on the surface or presses into it. Too short and the end embeds; that is a piercer visit, not a jewellery swap.
A hoop that is too small in diameter. Diameter is measured across the inside of the ring. A hoop smaller than the tissue it has to clear will pull; one that is much larger will hang and catch.
An end that is too wide for the space. A 4 mm gem on a nostril with a narrow alar rim sits at an angle and catches on fabric. End size is a comfort decision as much as a visual one.
A closure that does not suit daily wear. Hinged clickers are quick to open and close. L-bends and nose bones rely on tension and are easy to lose. Screws need a thread that matches, and threadless pieces need the pin to seat properly.
A material the listing does not actually name. “Surgical steel” describes an alloy family, not a grade. 316L is a stainless grade that contains nickel. It is a different material class from titanium. If sensitivity is a known issue for you, the material question is worth resolving before ordering rather than after.
What to check on a listing
- Gauge stated as a number, with the millimetre value if possible. 20G or 0.8 mm, not “thin”.
- Diameter or wearable length stated separately from the gauge. These are the fit numbers.
- End size in millimetres. A 3 mm crystal and a 1.5 mm ball are different decisions.
- Material named at grade level, not as a marketing adjective.
- The construction shown from the side. A front-on photo hides how the piece grips or closes, which is the part that decides whether it stays in.
- Quantity. Multi-packs are common, and a pack of four is four pieces of the same size.
Where to compare 20G nose jewelry
If you already know you wear 20G, start from the 20 gauge nose rings and studs collection, which is filtered to that size. If you are still working out your size, browse the wider nose jewelry collection and read each listing’s gauge line rather than the title.
Two current pieces show how differently the same gauge can be built: the 20 gauge nose hoop ring is a 5/16″ 316L steel hoop, while the 20G titanium black nose hoop is a 3/8″ piece in a different material class. Same gauge, different diameter, different material, different fit. Both are construction examples rather than fit recommendations, so check the live listing for the stated gauge, diameter, and material. For how material wording is documented on this site, see Material Certifications & Safety Info.
FAQ
Is 20 gauge big for a nose ring?
No. 20G is the thinnest size commonly sold for nostril jewellery, at 0.8 mm. It is smaller than 18G (1.0 mm) and 16G (1.2 mm). “Big” is not a useful way to describe gauge, because the scale runs backwards: the higher the number, the thinner the metal.
Is 18G or 20G better for a nose ring?
Neither is better in the abstract. The right size is the size the piercing was made and healed at. 20G reads finer and suits a subtle look; 18G carries a little more metal. Changing from 18G down to 20G leaves a loose fit, and changing from 20G up to 18G is a stretch rather than a swap.
Can I go from 18G to 20G in a nose ring?
A 20G piece will physically go into an 18G hole, but that does not make it a good fit. The thinner post sits loose, can migrate, and can let the hole tighten unevenly around it. Going up from 20G to 18G is a stretch and needs time and a piercer’s assessment, not a purchase.
Can you pierce your nose with a 20G needle?
What a piercing is done with is a decision for the piercer performing it, based on the tissue and the jewellery they intend to fit. It is not something to decide from a jewellery listing, and it is not a reason to change your own jewellery size afterwards.
How do I know if my nose ring is 20G or 18G?
Measure the post with a digital caliper: 0.8 mm is 20G, 1.0 mm is 18G, 1.2 mm is 16G. Measure the straight post, not the decorative end. If you cannot measure it, a studio can identify the size, and their record of the original piercing is more reliable than the piece currently in it.
Does a 20G nose ring fall out more easily?
A thinner post has less to hold against the hole, so a 20G piece in a piercing healed at a larger size can shift or work its way out. The closure type matters as much as the gauge: a hinged clicker stays put better than a nose bone held only by tension. Matching the gauge to the healed size is the main fix.
Can I wear a 20G nose ring in a fresh piercing?
Do not change a fresh, swollen, painful, or healing piercing to a different piece on your own schedule. Whether a piercing is ready for a change depends on the individual piercing and on assessment in person, and jewellery that is thinner than what the piercing was healed with is not a neutral swap.
Editorial note
Editorial note: This guide is jewellery education and shopping support, not medical advice. For fresh, painful, swollen, infected, irritated, or migrating piercings, consult a professional piercer or a qualified clinician. Gauge conversions follow American Wire Gauge nominal diameters, which describe wire rather than jewellery; the millimetre value stated on the individual listing is the number to trust. Reviewed for sizing language, material wording, and care boundaries.