Converting sheet metal gauge numbers to millimeters is as simple as following the chart below. For a more comprehensive gauge chart you can check out our sheet metal gauge chart here. This chart covers the common and uncommon sheet metal sizes for steel, aluminum and galvanized steel. Typically the even number gauges are used more frequently.
| Gauge # | Standard Steel (mm) | Non-Ferrous / Aluminum (mm) | Galvanized Steel (mm) |
|---|---|---|---|
| 000000 | - | 14.732 | - |
| 00000 | - | 13.119 | - |
| 0000 | - | 11.684 | - |
| 000 | - | 10.404 | - |
| 00 | - | 9.266 | - |
| 0 | - | 8.252 | - |
| 1 | - | 7.348 | - |
| 2 | - | 6.543 | - |
| 3 | 6.073 | 5.827 | - |
| 4 | 5.695 | 5.189 | - |
| 5 | 5.314 | 4.620 | - |
| 6 | 4.935 | 4.115 | - |
| 7 | 4.554 | 3.665 | - |
| 8 | 4.176 | 3.264 | 4.270 |
| 9 | 3.797 | 2.906 | 3.891 |
| 10 | 3.416 | 2.588 | 3.510 |
| 11 | 3.038 | 2.304 | 3.132 |
| 12 | 2.657 | 2.052 | 2.753 |
| 13 | 2.278 | 1.829 | 2.372 |
| 14 | 1.897 | 1.628 | 1.994 |
| 15 | 1.709 | 1.450 | 1.803 |
| 16 | 1.519 | 1.290 | 1.613 |
| 17 | 1.367 | 1.151 | 1.461 |
| 18 | 1.214 | 1.024 | 1.311 |
| 19 | 1.062 | .912 | 1.158 |
| 20 | .912 | .813 | 1.006 |
| 21 | .836 | .724 | .930 |
| 22 | .759 | .643 | .853 |
| 23 | .683 | .574 | .777 |
| 24 | .607 | .511 | .701 |
| 25 | .531 | .455 | .627 |
| 26 | .455 | .404 | .551 |
| 27 | .417 | .361 | .513 |
| 28 | .378 | .320 | .475 |
| 29 | .343 | .287 | .437 |
| 30 | .305 | .254 | .399 |
| 31 | .267 | .226 | .361 |
| 32 | .246 | .203 | .340 |
| 33 | .229 | .180 | - |
| 34 | .208 | .160 | - |
| 35 | .191 | .140 | - |
| 36 | .170 | .127 | - |
| 37 | .163 | .114 | - |
| 38 | .152 | .102 | - |
| 39 | - | .089 | - |
| 40 | - | .079 | - |