Sheet Metal Gauge Charts
Gauge-to-thickness for steel, stainless and aluminium — exact standard values in inch and mm, with a converter. Remember: the same gauge number is a different thickness in each material.
Gauge to thickness, all three materials
| Gauge | Steel in · mm | Stainless steel in · mm | Aluminium in · mm |
|---|---|---|---|
| 3 | 0.2391 · 6.07 | — | — |
| 4 | 0.2242 · 5.69 | — | — |
| 5 | 0.2092 · 5.31 | — | — |
| 6 | 0.1943 · 4.94 | — | 0.162 · 4.11 |
| 7 | 0.1793 · 4.55 | 0.1875 · 4.76 | 0.1443 · 3.67 |
| 8 | 0.1644 · 4.18 | 0.1719 · 4.37 | 0.1285 · 3.26 |
| 9 | 0.1495 · 3.8 | 0.1563 · 3.97 | 0.1144 · 2.91 |
| 10 | 0.1345 · 3.42 | 0.1406 · 3.57 | 0.1019 · 2.59 |
| 11 | 0.1196 · 3.04 | 0.125 · 3.17 | 0.0907 · 2.3 |
| 12 | 0.1046 · 2.66 | 0.1094 · 2.78 | 0.0808 · 2.05 |
| 13 | 0.0897 · 2.28 | 0.0938 · 2.38 | 0.072 · 1.83 |
| 14 | 0.0747 · 1.9 | 0.0781 · 1.98 | 0.0641 · 1.63 |
| 15 | 0.0673 · 1.71 | 0.0703 · 1.79 | 0.0571 · 1.45 |
| 16 | 0.0598 · 1.52 | 0.0625 · 1.59 | 0.0508 · 1.29 |
| 17 | 0.0538 · 1.37 | 0.0563 · 1.43 | 0.0453 · 1.15 |
| 18 | 0.0478 · 1.21 | 0.05 · 1.27 | 0.0403 · 1.02 |
| 19 | 0.0418 · 1.06 | 0.0438 · 1.11 | 0.0359 · 0.912 |
| 20 | 0.0359 · 0.912 | 0.0375 · 0.952 | 0.032 · 0.813 |
| 21 | 0.0329 · 0.836 | 0.0344 · 0.874 | 0.0285 · 0.724 |
| 22 | 0.0299 · 0.759 | 0.0313 · 0.795 | 0.0253 · 0.643 |
| 23 | 0.0269 · 0.683 | 0.0281 · 0.714 | 0.0226 · 0.574 |
| 24 | 0.0239 · 0.607 | 0.025 · 0.635 | 0.0201 · 0.511 |
| 25 | 0.0209 · 0.531 | 0.0219 · 0.556 | 0.0179 · 0.455 |
| 26 | 0.0179 · 0.455 | 0.0188 · 0.478 | 0.0159 · 0.404 |
| 27 | 0.0164 · 0.417 | — | — |
| 28 | 0.0149 · 0.378 | 0.0156 · 0.396 | — |
Gauge is not a unit — it is three different lookup tables that happen to share the numbers. 16 gauge steel is 0.0598″; 16 gauge aluminium is 0.0508″, thinner by 15%. Ordering or programming by gauge number without naming the material is how the wrong stock arrives.