THREE BASIC MEASUREMENTS

What Do Gauge, Barbell Length and Ring Diameter Mean?

Piercing jewelry measurements tell a piercer how thick a piece is and how much space it occupies in the chosen placement. The Association of Professional Piercers (APP) explains the U.S. convention in its Procedure Manual: jewelry thickness is commonly given as gauge, and it explains how a ring's diameter and a barbell's length are measured.

Most U.S. body jewelry sizing uses the Brown and Sharpe/American wire gauge convention. In many other countries, millimeters are the main way to express the same thickness. You may therefore see a product labeled 16G, 1.2 mm, or both.

A label such as 16G, 10 mm, 3 mm balls contains three different values. The 16G tells you the post thickness; 10 mm identifies the wearable shaft length for a straight barbell; and 3 mm describes the decorative ball diameter. Those measurements should not be added together to select the post length.

For a circular barbell, a label such as 16G x 10 mm diameter identifies the thickness of the curved wire and the inside diameter of the horseshoe. It does not mean that the balls are 10 mm apart or that the entire piece is 10 mm across the outside.

The APP emphasizes individual anatomy and placement when choosing initial jewelry. Two clients may have a piercing in the same general location while needing different lengths or inner diameters. Begin with a measured product option, then let the piercer assess whether it actually fits.

CONVERTING G TO MILLIMETERS

Body Jewelry Gauge Chart: 20G Through 10G

In gauge sizing, the numbers move in the opposite direction from thickness: smaller gauge numbers mean thicker jewelry. For example, 14G is thicker than 16G, and moving from 14G to 12G increases the shaft thickness. APP educational material also discusses these differences when explaining jewelry changes and stretching.

The APP's 2013 Procedure Manual includes both practical rounded millimeter values and more precise Brown and Sharpe conversions. Retail product labels commonly use the rounded figures.

Gauge conversions follow the APP Procedure Manual's chart. Rounded retail millimeter labels and mathematical gauge conversions are presented separately.

The important shopping rule is to preserve the actual thickness of the established piercing. A client wearing an 18G nostril piece should not select 20G or 16G solely because a particular style is available in that size. A qualified piercer can measure the channel and advise on any planned gauge change.

Similarly, the gauge of a barbell does not tell you how long its shaft should be. A 14G tongue barbell and a 14G navel barbell have a comparable nominal shaft thickness but very different shapes, lengths and wearing requirements.

THREE BARBELL SHAPES

Straight, Curved and Circular Barbells Explained

The APP describes a basic barbell as a shaft with two ends, usually balls, with one or both ends removable. The shaft may be straight, curved or circular. The shape influences how the jewelry sits in the piercing, while the gauge and wearable dimensions determine how it fits.

A curved barbell and a circular barbell are not interchangeable measurements simply because both have a bend. The curved banana is selected by its wearable length, while the circular horseshoe is selected by its inner diameter and end clearance.

Shape also affects how the jewelry moves around the anatomy. A ring may be suitable for one placement while a straight or curved post is preferable for another. The piercer should confirm the orientation and the available space before deciding on the jewelry style.

MORE WAYS JEWELRY IS SHAPED

Labrets, Nose Screws, Hinged Rings and Captive Bead Rings

Flat-Back Labret

A labret stud has a straight wearable post and a flat disc on one end instead of a projecting ball. The APP describes this style for lips, nostrils, tragus and helix piercings. A flat back is especially relevant when the rear of the jewelry sits against a nearby surface of skin or oral tissue. SVT Shop carries a 16G internally threaded titanium labret with a 3 mm ball in 6, 7, 8, 9, 10 and 12 mm lengths.

Nose Screw

A nostril screw has a decorative end on the outside and a bent section that helps it remain in position inside the nose without a conventional backing. Its shape must suit the wearer's nostril anatomy. SVT Shop carries 20G (about 0.8 mm) and 18G (about 1.0 mm) titanium nose screws, each with a 2 mm bezel-set crystal. The appropriate gauge and the orientation of the bent portion are professional fitting decisions.

Hinged Ring or Clicker

A hinged ring uses a movable segment with a closing mechanism. This creates an opening for insertion while leaving the piece ring-shaped when closed. SVT Shop offers 16G titanium hinged segment rings in inside diameters of 6, 7, 8, 9, 10, 12 and 14 mm. The dedicated forward-facing CZ septum design is also 16G, with 8 and 10 mm inner diameters. A piercer should check the hinge, seam and diameter for the particular piercing.

Captive Bead Ring

A captive bead ring (CBR) is a ring with a gap that holds a bead by pressure or tension. A circular barbell instead has two ends that screw onto its horseshoe-shaped shaft. Both can have a rounded appearance, but the closure mechanisms and handling are different.

For rings, keep the two dimensions separate: the gauge measures metal thickness and the inner diameter measures the space through the middle. Decorative beads, gems and closure components are additional specifications.

ACTUAL SVT SHOP OPTIONS

Body Jewelry Sizes by Piercing: What We Carry

The following chart lists product sizes available at SVT Shop for eleven piercing areas. It is a catalog reference for comparing products with a measurement already selected or checked by a piercer. The correct gauge, post length, ring diameter and closure always depend on individual anatomy, piercing placement and whether the piercing is healing or fully healed.

These are SVT Shop catalog sizes, not prescribed gauges or starting dimensions. The piercer decides what fits the person's anatomy, placement and healing stage.

Notice how the same gauge appears across very different pieces. SVT Shop offers multiple 16G styles, yet their shapes and wearable measurements are not equivalent. A 16G circular barbell in 10 mm diameter is not a replacement for a 16G straight barbell in 10 mm length.

The industrial barbell is included to identify the 32, 35 and 38 mm options available at SVT Shop. Because this particular model has external threads, and the APP standard for initial jewelry is internally threaded or threadless, the choice for a new industrial rests with your piercer.

The butterfly-back ear studs are likewise a separate shopping situation. Their 20G, 7 mm usable length describes the product sold. They come sterilized, but the APP's Procedure Manual is critical of butterfly closures, so for a new lobe piercing your piercer decides between them and a properly sized flat-back labret.

EAR AND FACIAL JEWELRY

Sizing Lobes, Helix, Tragus, Nostrils and Septums

Ear Lobes: Stud or Flat-Back Labret

The sterilized SVT Shop 20G CZ studs have 7 mm of usable length and butterfly backs. For a new lobe piercing, the piercer decides whether they suit; a smooth, appropriately sized flat-back, internally threaded or threadless piece can give the piercer a suitable initial-jewelry design to consider.

The linked titanium labret is available in 16G, with a range of 6–12 mm wearable lengths. The piercer determines whether that gauge and a particular length suit the actual lobe channel. A client should not select 16G merely because the product category includes ear jewelry.

Helix and Tragus: Post Length and Clearance

For cartilage locations, a flat-back labret can provide a low-profile rear surface. SVT Shop's 16G labret is available in 6, 7, 8, 9, 10 and 12 mm. The proper length depends on tissue thickness, placement angle and the amount of additional space initially required.

The APP highlights the importance of timely downsizing for a helix piercing. Once early swelling reduces, a post that remains excessively long can move or catch, especially if the wearer sleeps directly on the ear. The piercer should evaluate when a shorter post is appropriate.

SVT Shop also offers 16G hinged rings in inside diameters from 6 to 14 mm across the available size options. A professional should decide whether ring geometry suits the particular ear placement and healing stage.

Nostril: 20G and 18G Nose Screws

Nose stud shopping often begins with the question "Is this 18G or 20G?" At SVT Shop, both are available as titanium nose screws with 2 mm crystals. The 20G version is about 0.8 mm thick and the 18G version about 1.0 mm.

Gauge is only the first fitting question. The nose screw's bent inner portion is part of what keeps it in place, so the piercer assesses that shape against the individual's nostril anatomy. A visually small crystal does not determine how the post fits.

Septum: Circular Barbell or Hinged Ring

For a septum, SVT Shop offers a 16G circular barbell with 8, 10 or 12 mm inner diameter, plus a general-purpose 16G hinged ring range. The forward-facing CZ septum clicker is available at 8 and 10 mm inner diameter.

The inside diameter matters because it determines how the jewelry clears the anatomy and where its ends or decoration sit. The forward-facing CZ design also needs a professional assessment of the hinge, seam and prong-set ornament placement before use in a healing piercing.

A trusted piercer can help the client choose between a horseshoe appearance and a continuous-looking clicker, taking the stage of the piercing into account.

BODY AND ORAL PLACEMENTS

Sizing Eyebrow, Navel, Lip, Tongue and Nipple Jewelry

Eyebrow: Curved Banana Barbells

SVT Shop's high-polished titanium eyebrow banana is a 16G curved barbell with 3 mm balls, offered in 8, 10 and 12 mm lengths. The piercing's position and the distance between the two openings guide which wearable length and curve suit the individual.

Because the eyebrow area moves with facial expressions and may come into contact with clothing or towels, the fit should account for how the curved post sits during ordinary movement. The piercer assesses whether the jewelry has suitable room without unnecessary protrusion.

Navel: 14G Curved Belly Jewelry

The linked heart-CZ belly banana has 14G thickness and is offered in 10 and 12 mm lengths. It has internal threading. The piercing's depth, navel shape and how the area changes when sitting are part of the fitting decision.

An attractive decorative end does not replace the need for adequate clearance around the top and bottom openings. The piercer should check the shape and length during fitting, particularly when choosing an initial piece.

Lip and Labret: Flat-Back Posts

SVT Shop offers 16G internally threaded labrets with 3 mm ball ends and 6, 7, 8, 9, 10 and 12 mm posts. For lips, the inner disc and the shaft length are important because the jewelry sits near oral tissues.

The APP explains that oral piercings need an initial length that allows for swelling, followed by a professional downsize when appropriate. A post left too long may move against teeth and gums. The piercer chooses the correct point for changing it.

Tongue: 14G Straight Barbells

The linked tongue barbell is 14G with 5 mm balls and available lengths of 12, 14, 16 and 19 mm. These are different measured shafts for different fitting requirements, not a progression every client must purchase.

A new tongue piercing may require a longer initial post for swelling. Once the swelling has subsided, the APP advises returning to a qualified piercer for a shorter fit to limit unnecessary movement and contact with oral structures.

Nipple: 14G Barbells

SVT Shop's nipple barbell is 14G, internally threaded, with 4 mm balls and lengths of 10, 12, 14 and 16 mm. The piercer measures the specific anatomy and the channel created by the procedure, then selects the wearable length needed for that client.

A nipple barbell should not be sized from a general visual estimate alone. The usable length and end positions determine how the jewelry rests on the tissue, including the extra room needed during the initial healing stage.

MATERIAL, FINISH AND STERILE PACKAGING

What Makes Body Jewelry Suitable for a New Piercing?

Initial piercing jewelry requires a more careful selection than an accessory placed into an established, healed channel. The APP describes several connected factors: appropriate material, correct gauge, adequate length or diameter, smooth surface finish and a suitable jewelry design.

For titanium, the APP identifies Ti-6Al-4V ELI meeting ASTM F136 or ISO 5832-3, and commercially pure titanium meeting ASTM F67, among materials appropriate for initial use. A general label such as "Grade 23" is more useful when accompanied by a recognized implant-material specification.

SVT Shop's featured sterilized titanium jewelry line is identified as ASTM F136 titanium, with a high-polish finish and individual sealed sterile packaging displaying an expiration date. This line includes jewelry options suitable for new piercings because they are supplied sterilized, while the final decision about a specific piece belongs to the client's trusted professional piercer.

The piercer considers the package condition together with the selected gauge, wearable dimensions, closure and actual placement. A sterile package is one part of preparing a piece for initial use; correct anatomy-specific fitting is another.

For threaded designs, the APP favors internally threaded jewelry for initial piercings, while threadless press-fit jewelry is another accepted design. The surface of jewelry entering the channel should be smooth rather than carrying external screw threads across the tissue.

The linked industrial barbell has external threading; because the APP standard for initial jewelry is internally threaded or threadless, your piercer decides whether it suits a new industrial. The linked butterfly-back studs come sterilized, but the APP's manual is critical of butterfly closures, so for a new lobe piercing your piercer may prefer a flat-back labret.

SVT Shop's unsterilized steel jewelry line is for healed piercings. The APP separately explains that only appropriately specified steel alloys, such as ASTM F138 or ISO 5832-1, are included among initial-piercing material options. A generic steel label does not substitute for that specification and professional preparation.

For a fuller explanation of the material designation, sterile packaging and what a piercer checks, read SVT Shop's Implant-Grade Titanium and Sterilized Piercing Jewelry Guide.

HOW THE ENDS ATTACH

Internally Threaded vs. Threadless vs. Externally Threaded Jewelry

A barbell is not fully described by gauge and shaft length. The attachment style also matters, especially when the jewelry is being considered for a new piercing. The APP distinguishes the surfaces of internally threaded, externally threaded and threadless connections.

SVT Shop's internally threaded titanium barbell products include documented end-thread measurements: 0.9 mm threading on its 16G posts and 1.2 mm threading on its 14G posts. These figures refer to the attachment threads, not the post gauge or wearable shaft length.

When replacing a ball or decorative end, the thread dimensions, connection design and the specific post must match. An end identified as 3 mm describes the outside diameter of the ornament, while 0.9 mm refers to its internal-thread connection size in the corresponding linked product line.

Hinged clickers use another closure system. They should be selected by gauge, inner diameter and the fit of the movable segment. The piercer checks that any seam or hinge suits the position in which it will be worn.

For initial jewelry, the entire piece matters: a documented titanium alloy and individual sterile packaging should be considered together with the jewelry's surface, closure and sizing.

THE FIRST LENGTH MAY NOT BE THE FINAL LENGTH

Why Initial Piercing Jewelry Is Often Longer: Swelling and Downsizing

The APP explains that many new piercings need extra room in the initial jewelry to accommodate swelling. This can mean the first barbell or labret appears longer than a client expected from looking at photographs of healed piercings.

That additional room has a specific purpose during early healing. A post that fits too tightly can press on the tissue as swelling develops. The APP cautions about problems associated with undersized jewelry, including embedding and additional swelling.

As swelling decreases, the original post may become noticeably long. The APP calls the subsequent change to a shorter post downsizing. It is a professional fitting adjustment, not a cosmetic preference or an instruction to shorten a barbell immediately after the procedure.

Downsizing is particularly relevant to the helix and to oral piercings. The APP explains that a helix post left overly long can move excessively and affect the piercing angle, especially when the ear is slept on. For the mouth, unnecessary extra length can increase contact with teeth and gums.

The need for downsizing may arise before the piercing is fully healed. That is why the APP advises having a qualified piercer perform jewelry changes during the healing period, rather than changing the jewelry at home.

A client's existing jewelry measurement can be useful for a reorder, but it does not determine the correct initial length for a new procedure. The piercer should evaluate swelling, placement and anatomy directly.

UNDERSTAND YOUR EXISTING SIZE

How to Measure Body Jewelry You Already Wear

If you already have a fully healed piercing and want to replace a piece with the same general style, knowing the measurements of the jewelry can make the shopping process clearer. The most useful dimensions are the post gauge, wearable shaft length and inside ring diameter.

1. Identify the jewelry shape.

   Determine whether the piece is straight, curved, circular, a flat-back labret, a nostril screw or a hinged ring. This tells you which dimension to compare with the catalog.

2. Measure the shaft thickness.

   Use an appropriate body-jewelry gauge wheel or measuring tool to identify gauge. Compare the result with the 20G–10G chart rather than estimating thickness from the decorative balls.

3. Check the wearable length.

   For a straight barbell, measure the usable shaft between the ends. For a labret, measure the post between the flat disc and the decorative end. Curved barbells require a consistent measurement of the wearable section according to the jewelry style.

4. Check the inner ring diameter.

   For a ring or circular barbell, measure across the inside of the circle. Do not include the outer thickness of the wire or the decorative ends.

5. Record the end size and connection.

   Note the ball or top diameter and whether the jewelry is internally threaded, threadless or hinged. These are separate specifications from gauge and length.

6. Confirm the measurement with your piercer.

   A professional can assess whether the existing piece is correctly fitted and whether the same size should be used for the next purchase.

The measuring process is intended for understanding an existing piece, not removing jewelry from a healing piercing to inspect it. The APP explains that even established piercing channels can shrink quickly without jewelry in place. Seek professional assistance when removal or reinsertion is difficult.

Some jewelry arrives with a known catalog specification, making the process simpler. For example, a 16G x 8 mm circular barbell should be compared with the same gauge and inner diameter, while a 16G x 8 mm labret is a different shape measured by post length.

THE PROFESSIONAL FITTING CHECKPOINTS

When Should You Ask a Piercer About Jewelry Size?

A trusted piercer should select the jewelry used for a new piercing and review the fit when swelling changes. The APP also recommends professional assistance for changes during healing and for problems with size, style or material.

The APP's guidance on jewelry for healed piercings describes practical signs to consider before changing styles: the area should no longer be tender, the minimum healing period should have passed and normal crusting or discharge should have ended. Even then, the individual fit remains important.

If a piercing develops concerning swelling, embedding, unusual discharge or worsening symptoms, obtain prompt professional assessment. If an infection is suspected, the APP says to discuss with your physician whether quality jewelry should stay in place.

BEFORE YOU ORDER

Body Jewelry Size and Fit Buying Checklist

• I know the piercing location and current healing stage.
• I have confirmed the gauge with a qualified piercer.
• I understand the difference between wearable length and inner diameter.
• I chose straight, curved, circular, labret, nose screw or hinged jewelry intentionally.
• I checked the actual SVT Shop sizes rather than assuming a standard size.
• I know the ball or decorative end diameter where relevant.
• I checked the threading or closure type.
• I verified the specific material designation for initial jewelry.
• I considered the individually sterilized titanium options for a new piercing.
• I will let my trusted piercer approve the initial piece and fit.
• I know whether a professional downsize will be part of the care plan.
• I asked my piercer about the externally threaded industrial for a new piercing.
• I asked my piercer whether butterfly-back studs suit a new lobe piercing.
• I recorded the exact gauge, length or diameter for any replacement order.

COMMON SIZING QUESTIONS

Body Jewelry Size FAQ