Sheet Metal Gauge Chart
Gauge number to thickness in inches and mm for steel, galvanized, stainless and aluminum
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Converts sheet metal gauge numbers to thickness in millimeters and inches, and finds the gauge closest to a measured thickness. Tables cover sheet steel, galvanized steel, stainless steel, aluminum, BWG and SWG.
How to use
- Under "Gauge to thickness", choose the "Material" and the "Gauge". The thickness in mm and inches appears, with the same gauge in the other materials.
- If you have measured a sheet, enter it under "Thickness to nearest gauge" and choose "mm" or "in". The next thinner and next thicker gauge in each material are shown.
- The gauge table lists every gauge for the chosen material. Press "Print" to print only the table.
How it works
- The same number means a different thickness in each material. 16 gauge is about 1.52 mm in sheet steel, 1.61 mm galvanized, 1.59 mm stainless and 1.29 mm aluminum.
- Sheet steel gauges are defined by weight: thickness = weight per area ÷ 41.82 lb/ft² per inch, and the weight column shows this basis value. Galvanized gauges include the zinc coating, so they are thicker.
- Aluminum and other nonferrous sheet use the Brown & Sharpe gauge, the same series as AWG diameters. Wire current ratings are not covered.
- Every value was checked against at least two sources in October 2026. These are reference values; real sheet has thickness tolerances.
Questions and answers
- How thick is 16 gauge steel in mm?
- In sheet steel (Manufacturers' Standard Gauge) it is 0.0598 in, about 1.52 mm. Galvanized and stainless 16 gauge are slightly thicker; switch the material to compare.
- Does a higher gauge number mean thicker metal?
- No, a higher number is thinner. In sheet steel, 14 gauge is about 1.90 mm and 18 gauge is about 1.21 mm.
- What gauge is 1.2 mm sheet metal?
- Enter 1.2 under "Thickness to nearest gauge" to see the gauges on either side in each material, with the difference in mm. In sheet steel the closest is 18 gauge, about 1.21 mm.
- Should I order sheet metal by gauge?
- Because the same number differs between materials, the page recommends giving the thickness in mm or inches on drawings and orders as well.