Piercing gauge and size chart

Body jewelry is sized by gauge for thickness and by millimetres for length or diameter, which trips almost everyone up the first time. Gauge runs backwards: a smaller number means thicker jewelry.

Gauge to millimetres

Above 00g, sizes are quoted in millimetres or inches only.

Standard gauge by piercing

If you care about the gauge you will be wearing long term, say so before the needle. Going thicker later means stretching; going thinner means the channel shrinks and may not accept the original size again.

Length and diameter

Post length on a labret or barbell

Measure the wearable length: the straight section between the two ends, not including the ends themselves.

Your initial jewelry is deliberately longer than your final size to leave room for swelling. Once the swelling has gone you should downsize, typically at four to six weeks for soft tissue and six to ten weeks for cartilage. Leaving a long post in is one of the leading causes of irritation bumps.

Typical wearable lengths after downsizing:

These are starting points. Anatomy varies, and a piercer measuring your actual piercing beats any table.

Ring diameter

Diameter is measured across the inside of the ring, not the outside.

Too small and the ring presses on the channel constantly. Too large and it swings and catches. Have a piercer size a hoop the first time.

Ball and end size

Ends are sized in millimetres across: 2 mm, 2.5 mm, 3 mm, 4 mm and upward. Small flat ends are better while healing because they catch less. Large or spiky ends belong in healed piercings.

Measuring your own jewelry

A digital caliper is inexpensive and is the only accurate way to measure at home. Rulers are not precise enough at these sizes.

To measure a piece you already own:

• Gauge: measure the thickness of the post in millimetres, then put that figure into the converter at the top of this page.
• Length: measure the straight wearable section only.
• Diameter: measure the inside gap of a ring at its widest point.

If you are ordering jewelry for an existing piercing and you are unsure, take the piece to a studio. Most will measure it for you in a minute.

A note on stretching

Going up in gauge is stretching, and it needs to be done slowly. The general rule is one size at a time, waiting until the piercing is fully healed and settled at each size, using a taper and a lubricant, and never forcing.

Stretching too fast tears tissue and creates scar tissue that limits how far you can eventually go, and blowouts, where the channel lining pushes out through the back of the hole, are largely permanent. The Association of Professional Piercers publishes guidance on doing this safely.

What to buy

The right size in the wrong material still causes problems. Read the material guide for what to look for, and the threading guide for why the assembly matters as much as the metal.