What gauge are ear piercings?

Most ear piercings are 18 gauge (1.0mm) or 16 gauge (1.2mm) thick; lobes are sometimes 20 gauge (0.8mm). Gauge runs backwards — a smaller number means a thicker post. Post length and, for rings, internal diameter are the other measurements that matter; a piercer can measure yours before you buy jewellery.

By The Piercing Team at Lark & Berry · Published 2026-08-15

The sizes, first

Standard ear piercings in the UK are made at a small set of thicknesses, and almost all jewellery is built around them:

Professional studios most often pierce lobes at 18g and cartilage at 16g, though piercers vary this by anatomy and intended jewellery. Gun-pierced lobes from retail counters are typically thinner, around 20g — one of several reasons jewellery shopping gets confusing for people pierced outside studios.

Why the numbers run backwards

Gauge is the one sizing system in jewellery that works in reverse: the smaller the number, the thicker the metal. An 14g post is stout; a 20g post is fine. The system is inherited from wire manufacturing, where the gauge number historically related to how many times the wire was drawn through successively smaller dies — more draws, thinner wire, higher number. Nobody would design it that way today, and much of the world’s piercing industry increasingly just says millimetres instead. But gauge remains the language of jewellery listings, so the rule is worth committing to memory once: down in number, up in thickness. If you remember nothing else from this page, remember that 16g is thicker than 18g.

Thickness is only one of your measurements

A post that is the right gauge can still be the wrong jewellery, because piercing jewellery has a second dimension: length — how much post lies between the flat back disc and the front.

Length is where healing does its arithmetic. A fresh piercing is fitted with a deliberately longer post, because swelling is a normal part of early healing and the jewellery must leave room for it; a post fitted snugly on day one becomes a clamp by day three. Then, once the swelling has fully resolved, the piercer swaps in a shorter post — downsizing — so the jewellery no longer has spare length to lever about, catch on hair, or tilt the piercing while it matures. Skipping the downsize is one of the most common reasons ear piercings heal crooked or stay irritated, which is why Association of Professional Piercers-aligned aftercare treats it as part of the piercing, not an optional extra (safepiercing.org).

Healed piercings have a settled length too — commonly around 6mm to 8mm for lobes and 5mm to 6.5mm for much cartilage, but genuinely individual. Too short pinches; too long flops and snags.

Rings swap length for a third measurement: internal diameter, the distance across the inside of the ring. Too small a diameter presses into the piercing; too large spins and catches. The right diameter depends on the placement, where in the ear the piercing sits, and taste — another measurement to have taken rather than guessed.

Why knowing your sizes is worth the bother

Buying piercing jewellery without your sizes is buying shoes without your shoe size — except returns are worse, because worn jewellery is rarely returnable. Three numbers per piercing cover you: gauge, post length (or ring diameter), and the fitting type, threadless or threaded, covered in what threadless jewellery is. Keep them in your phone alongside which piercing they belong to; a curated ear of five piercings can easily involve three different sizes.

And when in doubt: any professional studio will measure your existing jewellery in under a minute, usually free or nearly so. It is the single easiest way to make every future jewellery purchase fit — and a good moment to confirm the material you’re wearing is what it should be, too.

See a professional if: you don’t know your sizes and want them measured, jewellery consistently pinches, tilts or hangs loose, you want to change gauge in either direction, or a healing piercing still has its long initial post months on — a piercer can measure accurately, advise on fit, and downsize at the right moment rather than by guesswork.