Sheet Metal Gauge Thickness Chart

Convert a sheet-metal gauge to thickness for steel, galvanized steel, stainless, and aluminum — shown in inches and millimeters. Because each material uses a different gauge standard, the same gauge number is a different thickness in each, so always pair the gauge with the material.

Sheet metal gauge to thickness in inches and millimeters by material
Gauge	Steel (in / mm)	Galvanized (in / mm)	Stainless (in / mm)	Aluminum (in / mm)
7	0.1793 / 4.55	—	—	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	0.1563 / 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
14	0.0747 / 1.90	0.0785 / 1.99	0.0781 / 1.98	0.0641 / 1.63
16	0.0598 / 1.52	0.0635 / 1.61	0.0625 / 1.59	0.0508 / 1.29
18	0.0478 / 1.21	0.0516 / 1.31	0.0500 / 1.27	0.0403 / 1.02
20	0.0359 / 0.91	0.0396 / 1.01	0.0375 / 0.95	0.0320 / 0.81
22	0.0299 / 0.76	0.0336 / 0.85	0.0313 / 0.79	0.0254 / 0.64
24	0.0239 / 0.61	0.0276 / 0.70	0.0250 / 0.64	0.0201 / 0.51
26	0.0179 / 0.45	0.0217 / 0.55	0.0187 / 0.48	0.0159 / 0.40
28	0.0149 / 0.38	0.0187 / 0.47	0.0156 / 0.40	0.0126 / 0.32
30	—	0.0157 / 0.40	0.0125 / 0.32	0.0100 / 0.25

Steel = Manufacturers' Standard Gauge · Galvanized includes zinc coating · Aluminum = Brown & Sharpe (AWG). Nominal values; actual stock varies within mill tolerance.

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Frequently asked questions

Is the same gauge the same thickness for every metal?: No. Steel, stainless, and aluminum use different gauge standards, so the same gauge number is a different thickness in each. For example, 16 gauge is 0.0598" in steel but 0.0508" in aluminum. Galvanized steel is slightly thicker than bare steel at the same gauge because of the zinc coating. Always specify both the material and the gauge (or, better, the actual thickness).
Does a higher gauge number mean thicker or thinner?: Thinner. Gauge runs inverse to thickness — a higher gauge number is a thinner sheet. 7 gauge is much thicker than 24 gauge.
Are these exact?: They are nominal values from the standard gauge tables. Real stock varies within mill tolerance, and coatings add thickness. For tight work, measure the actual sheet or call out a thickness with tolerance instead of a gauge.

Sheet Metal Gauge Thickness Chart

Sheet metal gauge to thickness in inches and millimeters by material
Gauge	Steel (in / mm)	Galvanized (in / mm)	Stainless (in / mm)	Aluminum (in / mm)
7	0.1793 / 4.55	—	—	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	0.1563 / 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
14	0.0747 / 1.90	0.0785 / 1.99	0.0781 / 1.98	0.0641 / 1.63
16	0.0598 / 1.52	0.0635 / 1.61	0.0625 / 1.59	0.0508 / 1.29
18	0.0478 / 1.21	0.0516 / 1.31	0.0500 / 1.27	0.0403 / 1.02
20	0.0359 / 0.91	0.0396 / 1.01	0.0375 / 0.95	0.0320 / 0.81
22	0.0299 / 0.76	0.0336 / 0.85	0.0313 / 0.79	0.0254 / 0.64
24	0.0239 / 0.61	0.0276 / 0.70	0.0250 / 0.64	0.0201 / 0.51
26	0.0179 / 0.45	0.0217 / 0.55	0.0187 / 0.48	0.0159 / 0.40
28	0.0149 / 0.38	0.0187 / 0.47	0.0156 / 0.40	0.0126 / 0.32
30	—	0.0157 / 0.40	0.0125 / 0.32	0.0100 / 0.25

Steel = Manufacturers' Standard Gauge · Galvanized includes zinc coating · Aluminum = Brown & Sharpe (AWG). Nominal values; actual stock varies within mill tolerance.

Frequently asked questions

Is the same gauge the same thickness for every metal?

No. Steel, stainless, and aluminum use different gauge standards, so the same gauge number is a different thickness in each. For example, 16 gauge is 0.0598" in steel but 0.0508" in aluminum. Galvanized steel is slightly thicker than bare steel at the same gauge because of the zinc coating. Always specify both the material and the gauge (or, better, the actual thickness).

Does a higher gauge number mean thicker or thinner?

Thinner. Gauge runs inverse to thickness — a higher gauge number is a thinner sheet. 7 gauge is much thicker than 24 gauge.

Are these exact?

They are nominal values from the standard gauge tables. Real stock varies within mill tolerance, and coatings add thickness. For tight work, measure the actual sheet or call out a thickness with tolerance instead of a gauge.