What Gauge Should My Piercing Jewelry Be?

If you've ever tried to buy body jewelry online and found yourself staring at "18G" or "16G" with no idea what that means, you're not alone. Gauge is one of those things nobody explains until you need to know it to buy new body jewelry.

Here's everything you need to know.

What Does Gauge Mean?

Gauge refers to the thickness of the post or bar that goes through your piercing. It's measured on a scale where—counterintuitively—a higher number means a thinner piece of jewelry.

So an 18G post is thinner than a 16G post. A 20G post is thinner than both.

Here’s a handy little chart:

Table 1: different gauge thickness in millimeters

The most common gauges for ear and body piercings are 18G and 16G. Most standard lobe piercings done at mall studios or with a piercing gun are done at 20G—which is why jewelry from those places tends to be thinner and less sturdy than what you'd get from a professional piercer.

 

Standard Gauges by Placement

Different piercings have standard gauge sizes based on the anatomy of the area and how much jewelry it can comfortably support. Here's a quick reference:

Table 2: common gauges for different piercings

These are standard starting gauges—your piercer may size up or down based on your anatomy. When in doubt, always check with the person who did your piercing.

What Happens if You Wear the Wrong Gauge?

It's not the end of the world—but it's worth knowing what to expect.

Too thick: your piercing hole will gradually stretch to accommodate the larger post. Over time, this just means your piercing is a slightly bigger gauge than it started.

Too thin: a post that's narrower than your piercing channel won't fill it properly, which can cause the hole to slowly close down around the thinner jewelry. If you go back to your original gauge later, it may feel tighter than before.

Neither scenario is an emergency—just something to be aware of when you're shopping for new pieces.

 

How to find out what gauge your piercing is

The easiest way is to ask the studio that did your piercing. Most keep records, and a quick message or call is faster than guessing.

If that's not an option, a piercing gauge wheel (a small tool with labeled holes) lets you measure the post of your existing jewelry to identify the gauge. They're inexpensive and widely available online.

You can also measure with a digital caliper if you have one. Just measure the diameter of the post and compare it to the millimeter chart above.

 

Post Length Matters Too

Gauge covers thickness, but post length is just as important—especially for cartilage piercings. A post that's too short will put pressure on the tissue and cause irritation. A post that's too long will move around too much and do the same.

Standard post lengths for ear piercings:

Table 3: standard post lengths for different piercing placements

For fresh piercings, your piercer will usually use a slightly longer post to accommodate swelling, then recommend downsizing once the initial healing settles—typically around 6–8 weeks in. Skipping the downsize is one of the most common reasons irritation bumps stick around longer than they should.

 

Oh Kira! Jewelry Gauges and Lengths at a Glance

Currently, we only offer flat back ear pieces (Marissa, Isla, Mina, Bay, and Soleil) with 18G and 6.00 mm posts, which is the standard for lobe, helix, conch, and tragus piercings. Meanwhile our naval piece (Sabrina) is 14G with a 10.0 mm curved barbell.

If you’re unsure about the different types of jewelry for different piercings, you can check our guide to the different types of body jewelry and message us if you have any further questions.

Jewelry Gauge and Material go hand in hand

Knowing your gauge is the first step. The second is making sure whatever you're putting in is made from a body-safe material. Not all metals are created equal—and even correctly sized jewelry made from the wrong metal can cause reactions, especially in cartilage piercings.