Sheet Metal Gauge Size Chart Standard Steel

Gauge (or gage) sizes are numbers that indicate the thickness of a piece of sheet metal, with a higher number referring to a thinner sheet. The equivalent thicknesses differ for each gauge size standard, which were developed based on the weight of the sheet for a given material. The Manufacturers' Standard Gage provides the thicknesses for standard steel, galvanized steel, and stainless steel. The Brown and Sharpe Gage, also known as the American Wire Gage (AWG), is used for most non ferrous metals, such as Aluminum and Brass. In the UK, the Birmingham Gage (BG) is used for a variety of metals and should not be confused with the Birmingham Wire Gage (BWG), which is used for wires. Lastly, a standard exists for Zinc in which a higher gauge number indicates a thicker sheet. The chart below can be used to determine the equivalent sheet thickness, in inches or millimeters, for a gauge number from the selected gauge size standard. The weight per unit area of the sheet can also be seen in pounds per square foot and kilograms per square meter.

	Thickness		Weight Per Area
Gauge	in	mm	lb/ft²	kg/m²
3	0.2391	6.073	9.754	47.624
4	0.2242	5.695	9.146	44.656
5	0.2092	5.314	8.534	41.668
6	0.1943	4.935	7.927	38.701
7	0.1793	4.554	7.315	35.713
8	0.1644	4.176	6.707	32.745
9	0.1495	3.797	6.099	29.777
10	0.1345	3.416	5.487	26.790
11	0.1196	3.038	4.879	23.822
12	0.1046	2.657	4.267	20.834
13	0.0897	2.278	3.659	17.866
14	0.0747	1.897	3.047	14.879
15	0.0673	1.709	2.746	13.405
16	0.0598	1.519	2.440	11.911
17	0.0538	1.367	2.195	10.716
18	0.0478	1.214	1.950	9.521
19	0.0418	1.062	1.705	8.326
20	0.0359	0.912	1.465	7.151
21	0.0329	0.836	1.342	6.553
22	0.0299	0.759	1.220	5.955
23	0.0269	0.683	1.097	5.358
24	0.0239	0.607	0.975	4.760
25	0.0209	0.531	0.853	4.163
26	0.0179	0.455	0.730	3.565
27	0.0164	0.417	0.669	3.267
28	0.0149	0.378	0.608	2.968
29	0.0135	0.343	0.551	2.689
30	0.0120	0.305	0.490	2.390
31	0.0105	0.267	0.428	2.091
32	0.0097	0.246	0.396	1.932
33	0.0090	0.229	0.367	1.793
34	0.0082	0.208	0.335	1.633
35	0.0075	0.191	0.306	1.494
36	0.0067	0.170	0.273	1.335
37	0.0064	0.163	0.261	1.275
38	0.0060	0.152	0.245	1.195