Gauge to Milimeters Converter

Sterling Silver Wire

As a hobbyist jewellery designer, I’ve found a constant struggle between measurements. Being taught in school the metric system, my parents would talk to me in terms of imperial because that is what they were taught when they were younger. Then once I went to school for goldsmithing and learned of gauges, this brought a whole new world of confusion to me. Even attempting to memorize the most commonly used gauges for jewellery making seemed to be a challenge. For those who would rather not memorize such an intense chart. I keep this chart beside my jewellery bench at all times.

This chart is for Gauge to Millimeter (mm)

Millimeters
Gauge (mm)
 1 7.348
 2 6.543
 . 6.35
 . 5.953
 3 5.827
 . 5.556
 4 5.189
 . 5.154
 . 4.762
 5 4.621
 . 4.366
 6 4.115
 . 3.969
 7 3.664
 . 3.572
 8 3.263
 . 3.175
 9 2.906
 . 2.778
 10 2.588
 . 2.381
 11 2.304
 12 2.052
 . 1.984
 13 1.828
 14 1.628
 . 1.588
 15 1.449
 16 1.291
 . 1.191
 17 1.149
 18 1.024
 19 0.912
 20 0.812
 . 0.795
 21 0.723
 22 0.644
 23 0.573
 24 0.511
 25 0.455
 26 0.405
 . 0.396
 27 0.36
 28 0.321
 29 0.286
 30 0.255
 31 0.226
 32 0.2
 33 0.18
 34 0.16
 35 0.142
 36 0.13
 37 0.114
 38 0.1

Often it is the project that you’re working on that will determine the gauge of wire you’ll need.

For making your own earring posts and French hooks, the most comfortable gauge for an standard ear hole is.9mm which or 19g.

Crocheting wire is also becoming very popular, and a recommend gauge for type of project would be a 30g or a 28g.

A common confusion with gauges is that the lower the gauge number, the smaller the wire. This is not true, thicker gauges are actually lower numbers. For example a 10g is 2.5mm, and then for a thin wire example a 30g is a 0.25mm.

Be sure when you are buying your wire that you consider the gauge as well as the hardness, and these two factors can affect your jewellery design. If you are planning on giving it a texture by hammering the wire, make sure that the wire you choose will be thick enough to take on that forced texture and not become brittle and break. As it may not happen right away, it may happen later on in your jewellery designs while you’re twisting the wire around and when you least expect it, such a catastrophe is easy to stop buy getting a slightly thicker wire with a softer hardness.