---
type: "chart"
name: "Sheet metal gauge chart"
gauge_row_count: 45
material_count: 4
units: "in / mm"
standard: "15 U.S.C. 206; Manufacturers' Standard Gauge; Brown & Sharpe / AWG"
verified: "August 1, 2026"
url: https://shopmath.org/charts/sheet-metal-gauge
---

# Sheet Metal Gauge Chart — Thickness by Gauge and Material

Every gauge number this reference covers, with its thickness in each material, inch and millimetre in the same cell. Gauge is a numbering scheme rather than a unit: the same number means a different thickness in steel, galvanized steel, aluminium and the 1893 U.S. Standard gauge, because each carries its own system. That is the comparison this chart exists to make obvious.

## Gauge Systems

| Material | Gauge system | Gauges | What it covers |
| --- | --- | --- | --- |
| Sheet Aluminium | B&S | 33 | Aluminium and other non-ferrous sheet on the Brown & Sharpe geometric series. |
| Galvanized Steel | galvanized-MSG | 24 | Galvanized sheet — MSG steel thickness plus a 2.5 oz/ft2 zinc coating allowance. |
| Sheet Steel | MSG | 34 | Mild, cold-rolled and hot-rolled sheet steel on the Manufacturers' Standard Gauge. |
| U.S. Standard Gauge | USG | 45 | The 1893 statutory gauge, as enacted, on a wrought-iron density basis. |

## Thickness by Gauge and Material

Each cell is inch / millimetre. A blank cell means that gauge number is not defined in that material's system.

| Gauge | Steel (in / mm) | Galvanized (in / mm) | Aluminium (in / mm) | U.S. Standard (in / mm) |
| --- | --- | --- | --- | --- |
| 0000000 ga |  |  |  | [0.5000 / 12.700](https://shopmath.org/gauges/us-standard/0000000.md) |
| 000000 ga |  |  |  | [0.4688 / 11.908](https://shopmath.org/gauges/us-standard/000000.md) |
| 00000 ga |  |  |  | [0.4375 / 11.112](https://shopmath.org/gauges/us-standard/00000.md) |
| 0000 ga |  |  |  | [0.4063 / 10.320](https://shopmath.org/gauges/us-standard/0000.md) |
| 000 ga |  |  |  | [0.3750 / 9.525](https://shopmath.org/gauges/us-standard/000.md) |
| 00 ga |  |  |  | [0.3438 / 8.733](https://shopmath.org/gauges/us-standard/00.md) |
| 0 ga |  |  |  | [0.3125 / 7.938](https://shopmath.org/gauges/us-standard/0.md) |
| 1 ga |  |  |  | [0.2813 / 7.145](https://shopmath.org/gauges/us-standard/1.md) |
| 2 ga |  |  |  | [0.2656 / 6.746](https://shopmath.org/gauges/us-standard/2.md) |
| 3 ga | [0.2391 / 6.073](https://shopmath.org/gauges/steel/3.md) |  | [0.2294 / 5.827](https://shopmath.org/gauges/aluminum/3.md) | [0.2500 / 6.350](https://shopmath.org/gauges/us-standard/3.md) |
| 4 ga | [0.2242 / 5.695](https://shopmath.org/gauges/steel/4.md) |  | [0.2043 / 5.189](https://shopmath.org/gauges/aluminum/4.md) | [0.2344 / 5.954](https://shopmath.org/gauges/us-standard/4.md) |
| 5 ga | [0.2092 / 5.314](https://shopmath.org/gauges/steel/5.md) |  | [0.1819 / 4.620](https://shopmath.org/gauges/aluminum/5.md) | [0.2188 / 5.558](https://shopmath.org/gauges/us-standard/5.md) |
| 6 ga | [0.1943 / 4.935](https://shopmath.org/gauges/steel/6.md) |  | [0.1620 / 4.115](https://shopmath.org/gauges/aluminum/6.md) | [0.2031 / 5.159](https://shopmath.org/gauges/us-standard/6.md) |
| 7 ga | [0.1793 / 4.554](https://shopmath.org/gauges/steel/7.md) |  | [0.1443 / 3.665](https://shopmath.org/gauges/aluminum/7.md) | [0.1875 / 4.762](https://shopmath.org/gauges/us-standard/7.md) |
| 8 ga | [0.1644 / 4.176](https://shopmath.org/gauges/steel/8.md) |  | [0.1285 / 3.264](https://shopmath.org/gauges/aluminum/8.md) | [0.1719 / 4.366](https://shopmath.org/gauges/us-standard/8.md) |
| 9 ga | [0.1495 / 3.797](https://shopmath.org/gauges/steel/9.md) | [0.1532 / 3.891](https://shopmath.org/gauges/galvanized/9.md) | [0.1144 / 2.906](https://shopmath.org/gauges/aluminum/9.md) | [0.1563 / 3.970](https://shopmath.org/gauges/us-standard/9.md) |
| 10 ga | [0.1345 / 3.416](https://shopmath.org/gauges/steel/10.md) | [0.1382 / 3.510](https://shopmath.org/gauges/galvanized/10.md) | [0.1019 / 2.588](https://shopmath.org/gauges/aluminum/10.md) | [0.1406 / 3.571](https://shopmath.org/gauges/us-standard/10.md) |
| 11 ga | [0.1196 / 3.038](https://shopmath.org/gauges/steel/11.md) | [0.1233 / 3.132](https://shopmath.org/gauges/galvanized/11.md) | [0.0907 / 2.304](https://shopmath.org/gauges/aluminum/11.md) | [0.1250 / 3.175](https://shopmath.org/gauges/us-standard/11.md) |
| 12 ga | [0.1046 / 2.657](https://shopmath.org/gauges/steel/12.md) | [0.1084 / 2.753](https://shopmath.org/gauges/galvanized/12.md) | [0.0808 / 2.052](https://shopmath.org/gauges/aluminum/12.md) | [0.1094 / 2.779](https://shopmath.org/gauges/us-standard/12.md) |
| 13 ga | [0.0897 / 2.278](https://shopmath.org/gauges/steel/13.md) | [0.0934 / 2.372](https://shopmath.org/gauges/galvanized/13.md) | [0.0720 / 1.829](https://shopmath.org/gauges/aluminum/13.md) | [0.0938 / 2.383](https://shopmath.org/gauges/us-standard/13.md) |
| 14 ga | [0.0747 / 1.897](https://shopmath.org/gauges/steel/14.md) | [0.0785 / 1.994](https://shopmath.org/gauges/galvanized/14.md) | [0.0641 / 1.628](https://shopmath.org/gauges/aluminum/14.md) | [0.0781 / 1.984](https://shopmath.org/gauges/us-standard/14.md) |
| 15 ga | [0.0673 / 1.709](https://shopmath.org/gauges/steel/15.md) | [0.0710 / 1.803](https://shopmath.org/gauges/galvanized/15.md) | [0.0571 / 1.450](https://shopmath.org/gauges/aluminum/15.md) | [0.0703 / 1.786](https://shopmath.org/gauges/us-standard/15.md) |
| 16 ga | [0.0598 / 1.519](https://shopmath.org/gauges/steel/16.md) | [0.0635 / 1.613](https://shopmath.org/gauges/galvanized/16.md) | [0.0508 / 1.290](https://shopmath.org/gauges/aluminum/16.md) | [0.0625 / 1.587](https://shopmath.org/gauges/us-standard/16.md) |
| 17 ga | [0.0538 / 1.367](https://shopmath.org/gauges/steel/17.md) | [0.0575 / 1.460](https://shopmath.org/gauges/galvanized/17.md) | [0.0453 / 1.151](https://shopmath.org/gauges/aluminum/17.md) | [0.0563 / 1.430](https://shopmath.org/gauges/us-standard/17.md) |
| 18 ga | [0.0478 / 1.214](https://shopmath.org/gauges/steel/18.md) | [0.0516 / 1.311](https://shopmath.org/gauges/galvanized/18.md) | [0.0403 / 1.024](https://shopmath.org/gauges/aluminum/18.md) | [0.0500 / 1.270](https://shopmath.org/gauges/us-standard/18.md) |
| 19 ga | [0.0418 / 1.062](https://shopmath.org/gauges/steel/19.md) | [0.0456 / 1.158](https://shopmath.org/gauges/galvanized/19.md) | [0.0359 / 0.912](https://shopmath.org/gauges/aluminum/19.md) | [0.0438 / 1.113](https://shopmath.org/gauges/us-standard/19.md) |
| 20 ga | [0.0359 / 0.912](https://shopmath.org/gauges/steel/20.md) | [0.0396 / 1.006](https://shopmath.org/gauges/galvanized/20.md) | [0.0320 / 0.813](https://shopmath.org/gauges/aluminum/20.md) | [0.0375 / 0.952](https://shopmath.org/gauges/us-standard/20.md) |
| 21 ga | [0.0329 / 0.836](https://shopmath.org/gauges/steel/21.md) | [0.0366 / 0.930](https://shopmath.org/gauges/galvanized/21.md) | [0.0285 / 0.724](https://shopmath.org/gauges/aluminum/21.md) | [0.0344 / 0.874](https://shopmath.org/gauges/us-standard/21.md) |
| 22 ga | [0.0299 / 0.759](https://shopmath.org/gauges/steel/22.md) | [0.0336 / 0.853](https://shopmath.org/gauges/galvanized/22.md) | [0.0253 / 0.643](https://shopmath.org/gauges/aluminum/22.md) | [0.0313 / 0.795](https://shopmath.org/gauges/us-standard/22.md) |
| 23 ga | [0.0269 / 0.683](https://shopmath.org/gauges/steel/23.md) | [0.0306 / 0.777](https://shopmath.org/gauges/galvanized/23.md) | [0.0226 / 0.574](https://shopmath.org/gauges/aluminum/23.md) | [0.0281 / 0.714](https://shopmath.org/gauges/us-standard/23.md) |
| 24 ga | [0.0239 / 0.607](https://shopmath.org/gauges/steel/24.md) | [0.0276 / 0.701](https://shopmath.org/gauges/galvanized/24.md) | [0.0201 / 0.511](https://shopmath.org/gauges/aluminum/24.md) | [0.0250 / 0.635](https://shopmath.org/gauges/us-standard/24.md) |
| 25 ga | [0.0209 / 0.531](https://shopmath.org/gauges/steel/25.md) | [0.0247 / 0.627](https://shopmath.org/gauges/galvanized/25.md) | [0.0179 / 0.455](https://shopmath.org/gauges/aluminum/25.md) | [0.0219 / 0.556](https://shopmath.org/gauges/us-standard/25.md) |
| 26 ga | [0.0179 / 0.455](https://shopmath.org/gauges/steel/26.md) | [0.0217 / 0.551](https://shopmath.org/gauges/galvanized/26.md) | [0.0159 / 0.404](https://shopmath.org/gauges/aluminum/26.md) | [0.0188 / 0.478](https://shopmath.org/gauges/us-standard/26.md) |
| 27 ga | [0.0164 / 0.417](https://shopmath.org/gauges/steel/27.md) | [0.0202 / 0.513](https://shopmath.org/gauges/galvanized/27.md) | [0.0142 / 0.361](https://shopmath.org/gauges/aluminum/27.md) | [0.0172 / 0.437](https://shopmath.org/gauges/us-standard/27.md) |
| 28 ga | [0.0149 / 0.378](https://shopmath.org/gauges/steel/28.md) | [0.0187 / 0.475](https://shopmath.org/gauges/galvanized/28.md) | [0.0126 / 0.320](https://shopmath.org/gauges/aluminum/28.md) | [0.0156 / 0.396](https://shopmath.org/gauges/us-standard/28.md) |
| 29 ga | [0.0135 / 0.343](https://shopmath.org/gauges/steel/29.md) | [0.0172 / 0.437](https://shopmath.org/gauges/galvanized/29.md) | [0.0113 / 0.287](https://shopmath.org/gauges/aluminum/29.md) | [0.0141 / 0.358](https://shopmath.org/gauges/us-standard/29.md) |
| 30 ga | [0.0120 / 0.305](https://shopmath.org/gauges/steel/30.md) | [0.0157 / 0.399](https://shopmath.org/gauges/galvanized/30.md) | [0.0100 / 0.254](https://shopmath.org/gauges/aluminum/30.md) | [0.0125 / 0.318](https://shopmath.org/gauges/us-standard/30.md) |
| 31 ga | [0.0105 / 0.267](https://shopmath.org/gauges/steel/31.md) | [0.0142 / 0.361](https://shopmath.org/gauges/galvanized/31.md) | [0.0089 / 0.226](https://shopmath.org/gauges/aluminum/31.md) | [0.0109 / 0.277](https://shopmath.org/gauges/us-standard/31.md) |
| 32 ga | [0.0097 / 0.246](https://shopmath.org/gauges/steel/32.md) | [0.0135 / 0.343](https://shopmath.org/gauges/galvanized/32.md) | [0.0080 / 0.203](https://shopmath.org/gauges/aluminum/32.md) | [0.0102 / 0.259](https://shopmath.org/gauges/us-standard/32.md) |
| 33 ga | [0.0090 / 0.229](https://shopmath.org/gauges/steel/33.md) |  | [0.0071 / 0.180](https://shopmath.org/gauges/aluminum/33.md) | [0.0094 / 0.239](https://shopmath.org/gauges/us-standard/33.md) |
| 34 ga | [0.0082 / 0.208](https://shopmath.org/gauges/steel/34.md) |  | [0.0063 / 0.160](https://shopmath.org/gauges/aluminum/34.md) | [0.0086 / 0.218](https://shopmath.org/gauges/us-standard/34.md) |
| 35 ga | [0.0075 / 0.190](https://shopmath.org/gauges/steel/35.md) |  | [0.0056 / 0.142](https://shopmath.org/gauges/aluminum/35.md) | [0.0078 / 0.198](https://shopmath.org/gauges/us-standard/35.md) |
| 36 ga | [0.0067 / 0.170](https://shopmath.org/gauges/steel/36.md) |  |  | [0.0070 / 0.178](https://shopmath.org/gauges/us-standard/36.md) |
| 37 ga |  |  |  | [0.0066 / 0.168](https://shopmath.org/gauges/us-standard/37.md) |
| 38 ga |  |  |  | [0.0063 / 0.160](https://shopmath.org/gauges/us-standard/38.md) |

_Sheet is supplied to a mill tolerance around these nominal thicknesses._

## Sources and Method for the Sheet Metal Gauge Chart

### Sheet-metal gauge thicknesses — steel, galvanized, aluminium, US Standard

- **Source**: 15 U.S.C. 206 statutory weights (public domain); MSG, galvanized and Brown & Sharpe formulas
- **Method**: computed
- **Verified against**: gauges: 137 checks passed across 1 harness(es)

### Formulas

**Brown & Sharpe geometric series (aluminium and non-ferrous)**

```text
t(n)  =  0.325 × (0.890525)^n   inches
```

### Assumptions

- Gauge is a numbering scheme, not a unit. A thickness is only meaningful with its material and gauge system stated.
- Dataset scope: EXCLUDED: stainless steel (genuinely ambiguous convention, only one source in hand), zinc, copper, brass, steel tube wall.

**Data last verified**: August 1, 2026

## Related pages

- Gauge reference by material: [Sheet metal gauge reference](https://shopmath.org/gauges.md)
- Drill sizes: [Drill size chart](https://shopmath.org/charts/drill-sizes.md)

---

*Source: [ShopMath](https://shopmath.org/charts/sheet-metal-gauge) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*