---
type: "sheet-metal-gauge"
gauge_number: "7"
material: "aluminum"
material_name: "Sheet Aluminium"
gauge_system: "B&S"
thickness_in: 0.1443
thickness_mm: 3.6649
standard: "15 U.S.C. 206; Manufacturers' Standard Gauge; Brown & Sharpe / AWG"
verified: "August 1, 2026"
url: https://shopmath.org/gauges/aluminum/7
---

# 7 Gauge Sheet Aluminium — Sheet Metal Thickness in Inches and Millimetres

7 gauge aluminium is 0.1443 in (3.665 mm) thick. That figure is on the B&S — gauge is a material-specific numbering scheme, not a unit, so the same number is a different thickness in another material.

- **Gauge**: 7
- **Material**: Sheet Aluminium
- **Gauge system**: B&S
- **Thickness**: 0.1443 in (3.665 mm)

## 7 Gauge Sheet Aluminium Thickness

| Property | Value |
| --- | --- |
| Thickness (in) | 0.1443 |
| Thickness (mm) | 3.665 |
| Gauge system | B&S |

## 7 Gauge Across Materials

The same gauge number in every material this reference covers. They differ because each material carries its own gauge system, not because one chart is wrong.

| Material | Gauge system | Thickness (in) | Thickness (mm) | lb/ft² | kg/m² |
| --- | --- | --- | --- | --- | --- |
| Sheet Aluminium (this page) | B&S | 0.1443 | 3.665 |  |  |
| [Sheet Steel](https://shopmath.org/gauges/steel/7.md) | MSG | 0.1793 | 4.555 | 7.500 | 36.62 |
| [U.S. Standard Gauge](https://shopmath.org/gauges/us-standard/7.md) | USG | 0.1875 | 4.763 | 7.500 | 36.62 |

## Sources and Method for 7 Gauge Sheet Aluminium

### Sheet Aluminium gauge thicknesses

- **Source**: 15 U.S.C. 206 (Act of Mar. 3, 1893, ch. 221, 27 Stat. 746) — U.S. Standard Gauge for sheet and plate iron and steel; 15 U.S.C. 206 statutory weights; MSG (41.82 lb/ft2 per inch), galvanized zinc allowance, and Brown & Sharpe formula per docs/research/data-sourcing.md §3.7
- **Method**: computed
- **Verified against**: Wikipedia Sheet metal, Standard sheet metal gauges table (CC BY-SA 4.0) — 137/137 checks passed at 0.05 mil

### Formulas

**Brown & Sharpe geometric series**

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

_The AWG / Brown & Sharpe series used for aluminium and other non-ferrous sheet._

### Assumptions

- Gauge is a numbering scheme, not a unit. A thickness is only meaningful with its material and gauge system stated.
- Sheet is supplied to a mill tolerance around these nominal thicknesses; measure the stock when the fit matters.
- 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

## Common Questions About 7 Gauge Sheet Aluminium

### How thick is 7 gauge aluminium?

7 gauge aluminium is 0.1443 in (3.665 mm) thick, on the B&S.

### What is 7 gauge in mm?

7 gauge aluminium is 3.665 mm. Gauge is not a unit — the same number means a different thickness in a different material, so the material has to be stated with it.

### Is 7 gauge the same thickness in every material?

No. 7 gauge is 0.1443 in in sheet aluminium, but 0.1793 in in sheet steel, 0.1875 in in u.s. standard gauge. Each material uses its own gauge system: B&S; MSG; USG.

## Related pages

- Thicker (lower gauge number): [6 gauge sheet aluminium](https://shopmath.org/gauges/aluminum/6.md) — 0.1620 in
- Thinner (higher gauge number): [8 gauge sheet aluminium](https://shopmath.org/gauges/aluminum/8.md) — 0.1285 in
- All sheet aluminium gauges: [Sheet Aluminium gauge chart](https://shopmath.org/gauges/aluminum.md)
- All materials and gauges: [Sheet metal gauge reference](https://shopmath.org/gauges.md)
- Full cross-material chart: [Sheet metal gauge chart](https://shopmath.org/charts/sheet-metal-gauge.md)

---

*Source: [ShopMath](https://shopmath.org/gauges/aluminum/7) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*