How to Measure Sheet Metal Gauge Thickness

The gauge of a sheet of metal is a reference to how thick it is. The higher the numbered gauge a piece of metal is, the thicker the piece is in millimeters. If you want to find out what gauge your sheet metal is, measure its thickness using a regular tape measure. Then, using a sheet metal gauge chart, you can match that thickness up with the appropriate numbered gauge of your product.

Step 1

Use a tape measure to find the thickness of your sheet metal piece. Use the millimeter hash marks to find the most accurate measurement possible.

Step 2

Multiply the number of millimeters by 0.03937 to convert to inches. If your measurement was 55 millimeters, for example, you would be left with 2.16535 inches.

Step 3

Compare the thickness of your sheet metal in inches to a sheet metal gauge chart to find the proper gauge of that particular piece. For example, if your sheet metal is 0.2391 inches, it would have a gauge of 3.