Measurement & Conversion
Gauge numbers confuse clients and apprentices alike because the system runs backwards: higher numbers mean thinner wire. These conversion tools make the clinical standard, millimetres, the universal language.
Gauge ConverterUpdated · V2
Convert gauge to millimetres and inches and check sizes at true scale on your screen.
- True-scale view calibrated with a bank card
- Measure your piece: reverse size lookup
- Printable wall chart and free embed
8 languages · EN FR IT DE ES NL PT TH
Open Gauge Converter →Jewelry Size VisualizerUpdated · V2
See body jewellery at real size on your screen, and try it on before buying.
- 1:1 visualizer and virtual try-on
- Photo measure and size compare
- Printable fit card and your collection
8 languages · EN FR IT DE ES NL PT TH
Open Jewelry Size Visualizer →See also: Body Jewelry Sizing -- Deep Dive Guide Full-length pillar guide: 4-part deep dive into the gauge system, barbell measurement, jewellery visualisation, and the science of ear stretching -- with professional FAQs and key takeaways.
Barbell Length
Barbell length is the most underestimated variable in piercing healing. A bar that is 2 mm too short creates constant pressure on the exit hole, and the piercing never fully heals. These calculators give you the right length before you order.
Stretching & Progression
Stretching is a collagen remodelling process, not a mechanical one. Collagen needs time to reorganise elastically after each increment. Rush it and you are trading a permanent scar for a shortcut of a few weeks.
Frequently Asked Questions
What is the difference between gauge and millimetre measurement?
Gauge is the historical American Wire Gauge (AWG) system where higher numbers mean thinner wire: 20g is 0.8 mm while 0g is 8.25 mm. The scale is non-linear and counter-intuitive, which is why professional piercers and manufacturers use millimetres as the precise clinical standard. The Gauge Converter on this page translates between both systems instantly.
How do I measure a client for a curved barbell versus an industrial barbell?
For a curved barbell, you measure the tissue depth (anatomy span) at the piercing site, the distance the barbell must travel through tissue from entry to exit, then add clearance for swelling (4 to 7 mm for fresh piercings, 2 to 4 mm for healed). For an industrial barbell, you measure the external hole-to-hole distance between the two outer edges of the piercing holes, then add ball protrusion (roughly one ball diameter) plus 2 to 4 mm healing clearance. The curved calculator accounts for arc-path geometry; the industrial calculator accounts for piercing angle and the lever mechanics of a rigid bar across two holes.
How long should I wait between stretching sizes?
The APP-recommended minimum intervals are 4 to 8 weeks for smaller gauges (18g to 6g), 6 to 8 weeks from 6g to 0g, and progressively longer above 10 mm where each stretch increment is proportionally larger relative to current diameter. Above 10 mm, most APP piercers recommend waiting until a plug sits with zero tension and no elasticity loss before attempting the next size, which can take 3 to 6 months per step. The Ear Stretching Timeline on this page calculates your personalised schedule from any starting gauge to any target size using these minimums.