Sheet metal gauge chart showing SWG (Standard Wire Gauge) conversions to millimetres and inches, covering a full range from thick plate to fine sheet.
This reference is used by fabricators, designers and engineers to quickly compare gauge sizes and specify accurate material thicknesses across copper, brass, stainless steel, aluminium and mild steel.
For clarity when ordering or manufacturing, we always recommend working in millimetres (mm), with gauge used as a secondary reference.
This sheet metal gauge chart converts Standard Wire Gauge (SWG) values into millimetres and inches, allowing quick comparison between traditional gauge sizes and modern metric measurements.
For projects requiring accurate thickness control and clean edges, precision cutting is typically carried out using CNC processes such as precision sheet metal laser cutting, delivering consistent results across both one-off and production work.
While gauge is still commonly used in specifica
This sheet metal gauge chart converts Standard Wire Gauge (SWG) values into millimetres and inches, allowing quick comparison between traditional gauge sizes and modern metric measurements.
For projects requiring accurate thickness control and clean edges, precision cutting is typically carried out using CNC processes such as precision sheet metal laser cutting, delivering consistent results across both one-off and production work.
While gauge is still commonly used in specifications, most fabrication, laser cutting and manufacturing processes work in millimetres for accuracy and consistency.
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Sheet metal gauge is a numerical system used to describe the thickness of metal sheet. In the Standard Wire Gauge (SWG) system, lower numbers represent thicker material, while higher numbers represent thinner material.
For example, 10 SWG is much thicker than 30 SWG. This can be confusing if you are used to working in millimetres, which is why gauge charts are commonly used to convert traditional gauge sizes into metric and imperial measurements.
For example, 1mm sheet metal is approximately 19–20 SWG, depending on the material.
Because gauge systems can vary depending on material and region, most modern fabrication, laser cutting and sheet metal supply work is specified in millimetres (mm). Gauge remains useful as a reference, especially when reading older drawings, legacy specifications or trade documents.
Sheet metal is available in a wide range of thicknesses and finishes, with options
Sheet metal gauge is a numerical system used to describe the thickness of metal sheet. In the Standard Wire Gauge (SWG) system, lower numbers represent thicker material, while higher numbers represent thinner material.
For example, 10 SWG is much thicker than 30 SWG. This can be confusing if you are used to working in millimetres, which is why gauge charts are commonly used to convert traditional gauge sizes into metric and imperial measurements.
For example, 1mm sheet metal is approximately 19–20 SWG, depending on the material.
Because gauge systems can vary depending on material and region, most modern fabrication, laser cutting and sheet metal supply work is specified in millimetres (mm). Gauge remains useful as a reference, especially when reading older drawings, legacy specifications or trade documents.
Sheet metal is available in a wide range of thicknesses and finishes, with options across copper, brass, zinc, stainless steel and aluminium for fabrication and design applications.
| SWG | INCH | MM | SWG | INCH | MM | |
|---|---|---|---|---|---|---|
| 7/0 | 0.500 | 12.70 | 23 | 0.024 | 0.61 | |
| 6/0 | 0.464 | 11.79 | 24 | 0.022 | 0.56 | |
| 5/0 | 0.432 | 10.97 | 25 | 0.020 | 0.51 | |
| 4/0 | 0.400 | 10.16 | 26 | 0.018 | 0.46 | |
| 3/0 | 0.372 | 9.45 | 27 | 0.016 | 0.42 | |
| 2/0 | 0.348 | 8.84 | 28 | 0.015 | 0.38 | |
| 1/0 | 0.324 | 8.24 | 29 | 0.014 | 0.35 | |
| 1 | 0.300 | 7.62 | 30 | 0.012 | 0.32 | |
| 2 | 0.276 | 7.01 | 31 | 0.012 | 0.30 | |
| 3 | 0.252 | 6.40 | 32 | 0.011 | 0.27 | |
| 4 | 0.232 | 5.89 | 33 | 0.010 | 0.25 | |
| 5 | 0.212 | 5.39 | 34 | 0.009 | 0.23 | |
| 6 | 0.192 | 4.88 | 35 | 0.008 | 0.21 | |
| 7 | 0.176 | 4.47 | 36 | 0.008 | 0.19 | |
| 8 | 0.160 | 4.06 | 37 | 0.007 | 0.17 | |
| 9 | 0.144 | 3.66 | 38 | 0.006 | 0.15 | |
| 10 | 0.128 | 3.25 | 39 | 0.005 | 0.13 | |
| 11 | 0.116 | 2.95 | 40 | 0.005 | 0.12 | |
| 12 | 0.104 | 2.64 | 41 | 0.004 | 0.11 | |
| 13 | 0.092 | 2.34 | 42 | 0.004 | 0.10 | |
| 14 | 0.080 | 2.03 | 43 | 0.004 | 0.09 | |
| 15 | 0.072 | 1.83 | 44 | 0.003 | 0.08 | |
| 16 | 0.064 | 1.63 | 45 | 0.003 | 0.07 | |
| 17 | 0.056 | 1.42 | 46 | 0.002 | 0.06 | |
| 18 | 0.048 | 1.22 | 47 | 0.002 | 0.05 | |
| 19 | 0.040 | 1.02 | 48 | 0.002 | 0.04 | |
| 20 | 0.036 | 0.91 | 49 | 0.001 | 0.03 | |
| 21 | 0.032 | 0.81 | 50 | 0.001 | 0.03 | |
| 22 | 0.028 | 0.71 |
Zinc uses a different gauge system (ZG), where higher numbers indicate thicker material — the opposite of SWG.
Zinc gauge is not commonly used in general sheet metal fabrication, but it can still appear in older specifications, roofing references and some zinc sheet descriptions. For this reason, it is useful to understand how zinc gauge relates to modern metric thicknesses.
For reference, here is a selection of zinc sheet gauges (ZG) and their nearest corresponding thickness in millimetres:
At Metal Sheets Ltd, we recommend specifying zinc sheet thickness in millimetres wherever possible, as this avoids confusion between zinc gauge and other gauge systems.
View our zinc sheet range or visit our wood screw gauge chart for another useful sizing reference.
Metal Sheets Ltd supplies a wide range of sheet metals in different sizes, thicknesses and finishes, including copper sheet, brass sheet, zinc sheet, aluminium sheet and stainless steel sheet.
We supply full sheets and part sheets, with material sizes depending on the metal type and finish selected. Many of our copper, brass and zinc sheets are available in large formats up to approximately 3000mm long, while aluminium, stainless steel and Corten steel sheets are available in a range of practical stock sizes for fabrication, interiors, signage and architectural projects.
Our in-house capabilities include guillotine cutting, forming, welding and fabrication, allowing us to support bespoke interior features, architectural metalwork and commercial projects from concept through to finished installation.
For precision-cut components, profiles and production work, our dedicated trade division MS Laser Services provides specialist precision sheet metal laser cutting for thin-gauge materials
For smaller cut-to-size orders and part sheets, visit our Metal Offcuts store. For bespoke fabrication or project enquiries, please contact Metal Sheets Ltd.
If you have a project requirement and would like to make some initial enquiries, please get in touch. Please contact us via email sales@metalsheets.co.uk, give us a call on 0151 526 4777, or fill the contact form. We’re looking forward to hearing from you.
Alternatively, shop safely and securely and purchase sheet metals via this website.
