Standard Sheet Metal Gauge Thickness Chart

A sheet metal gauge (sometimes spelled "gage") indicates the standard thickness of sheet metal for a specific material. As the gauge number increases, the material thickness decreases.

Sheet metal thickness gauges for steel are based on a weight of 41.82 pounds per square foot per inch of thickness. This is known as the Manufacturers' Standard Gage for Sheet Steel. For other materials, such as aluminum and brass, the thicknesses will be different. Thus, a 10 gauge steel sheet which has a thickness of 0.1345 inches will weigh 41.82*0.1345 = 5.625 pounds per square foot.

Examples: 16 ga CRS is 2.5 pounds per square foot. For 18 ga CRS the weight is 2.0 pounds per square foot and for 20 ga CRS the weight is 1.5 pounds per square foot.

Standard sheet metal gauges

Gauge	Steel	Carbon Steel eh	Galvanized Steel	Stainless Steel	Aluminum	Steel (mm)
07	0.179	-	-	-	-	4.547
08	0.165	0.1644	0.1681	0.1719	0.1285	4.191
09	0.150	0.1495	0.1532	0.1563	0.1144	3.810
10	0.135	0.1345	0.1382	0.1406	0.1019	3.429
11	0.120	0.1196	0.1233	0.1250	0.0907	3.048
12	0.105	0.1046	0.1084	0.1094	0.0808	2.677
13	0.09	-	-	0.094	0.072	2.286
14	0.075	0.0747	0.0785	0.0781	0.0641	1.905
15	0.067	-	-	0.07	0.057	1.702
16	0.060	0.0598	0.0635	0.0625	0.0508	1.524
17	0.054	-	-	0.056	0.045	1.372
18	0.047	0.0478	0.0516	0.0500	0.0403	1.1938
19	0.042	-	-	0.044	0.036	1.067
20	0.036	0.0359	0.0396	0.0375	0.0320	0.9144
21	0.033	-	-	0.034	0.028	0.838
22	0.03	-	-	0.031	0.025	0.762
23	0.027	-	-	0.028	0.023	0.686
24	0.024	-	-	0.025	0.02	0.61
25	0.021	-	-	0.022	0.018	0.533
26	0.018	-	-	0.019	0.017	0.457
27	0.016	-	-	0.017	0.014	0.406
28	0.015	-	-	0.016	-	0.381
29	0.014	-	-	0.014	-	0.356
30	0.012	-	-	0.013	-	0.305
31	-	-	-	0.011	-	-

Thickness is expressed in inches except for the mm column (1in = 25.4mm).
This table is for reference only and it is highly recommended that you check with a local supplier to establish what actual thickness values are used in your particular location.