12 gauge steel thickness and weight
0.1046 in · 2.66 mm · 4.272 lb/ft²
12 gauge sheet steel (Manufacturers' Standard Gauge) is 0.1046 in, or 2.66 mm, thick. It weighs 4.272 lb per square foot (20.86 kg/m²).
Weight of common sheet sizes
| Sheet | lb | kg |
|---|---|---|
| 4 × 8 ft | 136.7 | 62.0 |
| 4 × 10 ft | 170.9 | 77.5 |
| 5 × 10 ft | 213.6 | 96.9 |
| 1000 × 2000 mm | 92.0 | 41.7 |
| 1250 × 2500 mm | 143.7 | 65.2 |
| 1500 × 3000 mm | 206.9 | 93.9 |
12 gauge in other metals
| Material | Thickness (in) | Thickness (mm) | kg/m² |
|---|---|---|---|
| Sheet steel | 0.1046 | 2.66 | 20.86 |
| Galvanized steel | 0.1084 | 2.75 | 21.61 |
| Stainless steel | 0.1094 | 2.78 | 22.04 |
| Aluminum | 0.0808 | 2.05 | 5.54 |
Gauge numbers are tied to the material, so 12 gauge aluminum is not the same thickness as 12 gauge steel. When ordering, give the thickness in inches or millimetres.
Compared with nearby gauges
| Gauge | in | mm | lb/ft² | Thickness vs 12 ga |
|---|---|---|---|---|
| 9 gauge | 0.1495 | 3.80 | 6.105 | +43 % |
| 10 gauge | 0.1345 | 3.42 | 5.493 | +29 % |
| 11 gauge | 0.1196 | 3.04 | 4.884 | +14 % |
| 12 gauge | 0.1046 | 2.66 | 4.272 | — |
| 13 gauge | 0.0897 | 2.28 | 3.663 | −14 % |
| 14 gauge | 0.0747 | 1.90 | 3.051 | −29 % |
| 15 gauge | 0.0673 | 1.71 | 2.748 | −36 % |
A lower gauge number means a thicker sheet. The steps between gauges are not equal, because the gauge system started as a measure of weight per square foot rather than of thickness.
Metric and fractional equivalents
Outside the US, sheet is ordered in millimetres. The nearest standard metric thickness to 12 gauge (2.66 mm) is 2.5 mm, which weighs 19.63 kg/m². The nearest fraction of an inch is 7/64 in (0.1094 in). If a drawing calls for 12 gauge and you buy metric sheet, check whether the small difference in thickness matters for bending, welding or fit.
Weight of strips
Weight per running foot of a 12 gauge strip, for sheared blanks and formed parts.
| Strip width | lb per foot of length |
|---|---|
| 6 in | 2.14 |
| 12 in | 4.27 |
| 24 in | 8.54 |
| 36 in | 12.82 |
| 48 in | 17.09 |
Where 12 gauge is used
This range is common for enclosures, cabinets, tool boxes, car body and frame repair, brackets and light structural parts. Thickness tolerances for cold-rolled and hot-rolled sheet are set by ASTM A568 and depend on width, so the measured thickness can be a few thousandths of an inch off the nominal gauge value.
Frequently asked questions
How thick is 12 gauge steel in mm?
12 gauge sheet steel is 2.66 mm (0.1046 in). The nearest standard metric sheet is 2.5 mm.
How much does a 4 × 8 sheet of 12 gauge steel weigh?
About 136.7 lb (62.0 kg): 4.272 lb/ft² × 32 ft².
Is 12 gauge thicker than 13 gauge?
Yes. A lower gauge number is thicker: 12 gauge is 0.1046 in, 13 gauge is 0.0897 in, and 11 gauge is 0.1196 in.
Is 12 gauge the same as 7/64 inch?
Close: 12 gauge is 0.1046 in and 7/64 in is 0.1094 in. Material ordered as 7/64 in is made to that fractional thickness, so it is about 5 % thicker than 12 gauge.
How thick is 12 gauge galvanized steel?
0.1084 in (2.75 mm), slightly more than plain 12 gauge because the gauge includes the zinc coating.
Is 12 gauge aluminum the same thickness as steel?
No. 12 gauge aluminum is 0.0808 in (2.05 mm); aluminum uses a different gauge table.
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Data adapted from Wikipedia, "Sheet metal" (CC BY-SA 4.0).