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Sheet metal gauge chart

Gauge to thickness for steel, galvanized, stainless and aluminium, in inches and millimetres, with sheet weight. One gauge number has four different answers, so pick the material first.

Gauge lookup

Material

Gauge

Thickness0.0598in

Millimetres1.52mm

Sheet weight2.44lb/ft²

16 gauge steel is 0.0598 inches. Uncoated mild and carbon steel sheet.

Steel: Manufacturers' Standard Gauge (MSG)

Gauge	Inches	mm	lb/ft²
3	0.2391	6.07	9.76
4	0.2242	5.69	9.16
5	0.2092	5.31	8.54
6	0.1943	4.94	7.93
7	0.1793	4.55	7.32
8	0.1644	4.18	6.71
9	0.1495	3.80	6.11
10	0.1345	3.42	5.49
11	0.1196	3.04	4.88
12	0.1046	2.66	4.27
13	0.0897	2.28	3.66
14	0.0747	1.90	3.05
15	0.0673	1.71	2.75
16	0.0598	1.52	2.44
17	0.0538	1.37	2.20
18	0.0478	1.21	1.95
19	0.0418	1.06	1.71
20	0.0359	0.91	1.47
21	0.0329	0.84	1.34
22	0.0299	0.76	1.22
23	0.0269	0.68	1.10
24	0.0239	0.61	0.98
25	0.0209	0.53	0.85
26	0.0179	0.45	0.73
27	0.0164	0.42	0.67
28	0.0149	0.38	0.61
29	0.0135	0.34	0.55
30	0.0120	0.30	0.49

Each material uses a different standard. Steel and galvanised follow the Manufacturers’ Standard Gauge, stainless has its own series, and aluminium follows Brown & Sharpe. That is why 16 gauge is 0.0598 in steel, 0.0625 in stainless and 0.0508 in aluminium. Thicknesses are nominal and mill tolerance applies, so measure the sheet for anything structural.

What sheet metal gauge actually means

Sheet metal gauge is a number that stands for a thickness, and the thickness it stands for depends entirely on the material. Sixteen gauge is 0.0598 inches in steel, 0.0625 inches in stainless and 0.0508 inches in aluminium, because those three materials are tabulated under three different published standards.

The steel scale, the Manufacturers Standard Gauge, is defined by weight rather than by thickness: each gauge number is a nominal weight per square foot, converted to a thickness using 41.82 pounds per square foot per inch. Galvanized steel uses the same series with the zinc coating included, which is why a galvanized sheet is always slightly thicker than an uncoated one of the same gauge. Aluminium, brass and copper follow Brown and Sharpe, the same geometric series as American Wire Gauge.

In all of them the scale runs backwards, so a larger gauge number is a thinner sheet.

Full gauge chart, all four materials

Nominal thickness in decimal inches. Blank cells are gauge numbers that material is not commonly supplied in.

Sheet metal gauge to thickness. Scroll sideways for more materials.
Gauge	Steel		Galvanized		Stainless		Aluminium
Gauge	in	mm	in	mm	in	mm	in	mm
3	0.2391	6.07	–	–	0.2500	6.35	0.2294	5.83
4	0.2242	5.69	–	–	0.2344	5.95	0.2043	5.19
5	0.2092	5.31	–	–	0.2187	5.55	0.1819	4.62
6	0.1943	4.94	–	–	0.2031	5.16	0.1620	4.11
7	0.1793	4.55	–	–	0.1875	4.76	0.1443	3.67
8	0.1644	4.18	0.1681	4.27	0.1719	4.37	0.1285	3.26
9	0.1495	3.80	0.1532	3.89	0.1562	3.97	0.1144	2.91
10	0.1345	3.42	0.1382	3.51	0.1406	3.57	0.1019	2.59
11	0.1196	3.04	0.1233	3.13	0.1250	3.18	0.0907	2.30
12	0.1046	2.66	0.1084	2.75	0.1094	2.78	0.0808	2.05
13	0.0897	2.28	0.0934	2.37	0.0938	2.38	0.0720	1.83
14	0.0747	1.90	0.0785	1.99	0.0781	1.98	0.0641	1.63
15	0.0673	1.71	0.0710	1.80	0.0703	1.79	0.0571	1.45
16	0.0598	1.52	0.0635	1.61	0.0625	1.59	0.0508	1.29
17	0.0538	1.37	0.0575	1.46	0.0562	1.43	0.0453	1.15
18	0.0478	1.21	0.0516	1.31	0.0500	1.27	0.0403	1.02
19	0.0418	1.06	0.0456	1.16	0.0437	1.11	0.0359	0.91
20	0.0359	0.91	0.0396	1.01	0.0375	0.95	0.0320	0.81
21	0.0329	0.84	0.0366	0.93	0.0344	0.87	0.0285	0.72
22	0.0299	0.76	0.0336	0.85	0.0312	0.79	0.0253	0.64
23	0.0269	0.68	0.0306	0.78	0.0281	0.71	0.0226	0.57
24	0.0239	0.61	0.0276	0.70	0.0250	0.64	0.0201	0.51
25	0.0209	0.53	0.0247	0.63	0.0219	0.56	0.0179	0.45
26	0.0179	0.45	0.0217	0.55	0.0187	0.47	0.0159	0.40
27	0.0164	0.42	0.0202	0.51	0.0172	0.44	0.0142	0.36
28	0.0149	0.38	0.0187	0.47	0.0156	0.40	0.0126	0.32
29	0.0135	0.34	0.0172	0.44	0.0141	0.36	0.0113	0.29
30	0.0120	0.30	0.0157	0.40	0.0125	0.32	0.0100	0.25

Sources: Manufacturers’ Standard Gauge for Sheet Steel (steel, galvanized), the manufacturers’ stainless sheet series, and Brown & Sharpe (aluminium). Published under CC BY 4.0, so reuse with a link back is welcome.

Which standard applies to which material

Steel

Manufacturers' Standard Gauge (MSG). Uncoated mild and carbon steel sheet.

Galvanized

MSG plus G90 zinc coating. Thicker than uncoated steel at the same gauge, because the zinc counts.

Stainless

Manufacturers' standard for stainless sheet. A separate series again. 16 gauge stainless is 0.0625 in, steel is 0.0598 in.

Aluminium

Brown & Sharpe (AWG). Also used for brass and copper sheet.

How to read a gauge chart

Identify the material

Steel, galvanized, stainless and aluminium each use a different gauge standard. A magnet separates plain and galvanized steel from most stainless and all aluminium.

Read the thickness across from the gauge number

Find the gauge row and read the column for your material. The result is the nominal thickness in decimal inches.

Allow for mill tolerance

Published gauge thicknesses are nominal. Real sheet varies by a few thousandths of an inch, so measure the actual material for anything structural or for a close-fitting part.

Common questions

How thick is 16 gauge steel?

Sixteen gauge uncoated steel is 0.0598 inches, or 1.52 mm. Sixteen gauge stainless is thicker at 0.0625 inches, and 16 gauge aluminium is thinner at 0.0508 inches. The gauge number alone does not give a thickness without knowing the material.

Why does the same gauge mean different thicknesses?

Because each material follows a different standard. Steel and galvanized steel use the Manufacturers Standard Gauge, which is defined by weight per square foot. Stainless has its own manufacturers series. Aluminium, brass and copper follow the Brown and Sharpe scale, which is the same series as American Wire Gauge.

Is a higher gauge number thicker or thinner?

Thinner. The scale runs backwards, so 10 gauge is substantially thicker than 20 gauge. The number originally counted how many times the sheet was passed through the rolling mill, and more passes meant thinner material.

Why is galvanized steel thicker than plain steel at the same gauge?

Because the zinc coating is included in the measurement. A G90 coating adds roughly 0.0037 inches, so 16 gauge galvanized is 0.0635 inches against 0.0598 inches for the uncoated sheet.

How do I measure the gauge of a sheet I already have?

Measure the thickness with a caliper or micrometer, then match it to the column for that material. Switch the tool above to thickness-to-gauge and it will find the nearest standard gauge. Measure away from any edge, since shearing deforms the material locally.