You can measure your ear gauge size at home using a basic millimeter ruler, a pair of calipers, or even by test-fitting jewelry you already own. The key is measuring the diameter of your plug, tunnel, or piercing hole in millimeters, then matching that number to the standard gauge chart. A standard ear piercing starts at 20g or 18g (about 1 mm), and stretched sizes work upward from there.
What You’re Actually Measuring
Gauge size refers to the diameter of the jewelry that fits through your piercing. The gauge system runs counterintuitively: smaller numbers mean larger sizes. An 18g is about 1 mm across, while a 0g is 8 mm and a 00g is 10 mm. Once you pass 00g, the gauge system stops and sizes are listed in plain millimeters or fractions of an inch.
Whether you’re measuring a piece of jewelry or the hole in your ear, you’re looking for the same thing: the widest point straight across the circle, in millimeters.
Three Ways to Measure at Home
Digital Calipers
A digital caliper is the most accurate tool for this. You can find one online or at a hardware store for under $15. To use it, slide the jaws open wider than your plug or tunnel, place the jewelry between the jaws, then close them until they rest snugly on either side. The screen displays the exact measurement in millimeters. No guessing, no squinting at tiny lines.
If you have a brass sliding caliper instead of a digital one, the process is the same. You just read the measurement from the ruler markings where the sliding line rests, rather than from a screen.
Millimeter Ruler
A standard metric ruler works if you don’t have calipers. Lay your plug flat on a table and line up one edge with the zero mark. Read across to the opposite edge. This method is less precise, especially at smaller sizes where a fraction of a millimeter matters, but it’s good enough to identify your general size. Make sure you’re reading the millimeter side, not centimeters or inches.
Test-Fitting Known Jewelry
If you have labeled jewelry in a few sizes, you can simply try inserting them. The piece that slides in comfortably without resistance is your current size. This is especially useful when you’re trying to figure out the size of a piercing hole rather than a piece of jewelry.
Measuring Your Ear Without Jewelry
If you want to measure the piercing hole itself, remove your jewelry and measure the opening across its widest point. Calipers work best here because you can gently position them at the edges of the hole. A ruler held up to a mirror can give you a rough estimate, but it’s harder to be precise.
Keep in mind that your ear will start to shrink once jewelry is removed, especially if you’ve been stretching recently. Measure promptly after taking out your plugs for the most accurate reading. If you’ve been without jewelry for a while, the hole may have closed down a size or two from where you last were.
Why Plug Style Affects Measurement
Not all plugs are the same diameter along their entire length, and this matters when you’re measuring.
- No-flare (flat) plugs are a smooth cylinder with the same diameter from front to back. Measure anywhere along the body and you’ll get the correct gauge size.
- Single-flare plugs have one wider edge on the front and an O-ring on the back to hold them in place. The flared edge is larger than the actual gauge. Measure the smooth body of the plug, not the flare, to get your true size.
- Double-flare plugs have wider edges on both sides, with no O-ring needed. Again, measure the narrowest part of the body between the two flares. The flares themselves are typically 0.5 to 1 mm larger than the labeled size, which is why double-flare plugs require your ears to be slightly larger than the stated gauge to insert them comfortably.
If you measure across the flare instead of the body, you’ll overestimate your size and may order jewelry that’s too loose or attempt a stretch that’s too aggressive.
Standard Gauge to Millimeter Conversion
Once you have your millimeter measurement, match it to the chart below to find your gauge size.
- 18g: 1.0 mm
- 16g: 1.2 mm
- 14g: 1.6 mm
- 12g: 2 mm
- 10g: 2.4 mm
- 8g: 3.2 mm
- 6g: 4 mm
- 4g: 5 mm
- 2g: 6 mm
- 0g: 8 mm
- 00g: 10 mm
Beyond 00g, sizes are listed in millimeters: 11 mm, 12 mm (1/2 inch), 14 mm, 16 mm (5/8 inch), 19 mm (3/4 inch), 22 mm (7/8 inch), 25 mm (1 inch), and up to 51 mm (2 inches).
Notice the jumps aren’t even. Going from 2g to 0g is a 2 mm increase, while going from 14g to 12g is less than half a millimeter. This is why measuring precisely matters more at certain points in the stretching process. A 1 mm difference at smaller sizes could mean skipping a gauge entirely.
Common Measurement Mistakes
The most frequent error is measuring the wrong part of the jewelry. Measure straight across the widest point of the wearable area (the part that sits inside your ear), not the length from front to back. For plugs with flares, ignore the flares entirely.
Another common issue is rounding. If your measurement falls between two standard sizes, say 7 mm, your actual size is between 2g (6 mm) and 0g (8 mm). Some brands sell half sizes to bridge these gaps. Don’t round up and assume you’re at the next gauge.
Finally, cheap rulers with poorly printed markings can be off by a millimeter or more. If accuracy matters to you, a digital caliper is worth the small investment. It removes all the guesswork and reads out to a tenth of a millimeter.