Gauge to mm Converter

Convert sheet metal gauge to millimeters for Galvanized Steel, Stainless Steel and Aluminum.

Full Gauge Thickness Chart

Gauge	Thickness (mm)	Thickness (inches)
8 Gauge	4.27 mm	0.1681 in
9 Gauge	3.89 mm	0.1532 in
10 Gauge	3.51 mm	0.1382 in
11 Gauge	3.13 mm	0.1233 in
12 Gauge	2.75 mm	0.1084 in
13 Gauge	2.37 mm	0.0934 in
14 Gauge	1.99 mm	0.0785 in
15 Gauge	1.80 mm	0.0710 in
16 Gauge	1.61 mm	0.0635 in
17 Gauge	1.46 mm	0.0575 in
18 Gauge	1.31 mm	0.0516 in
19 Gauge	1.16 mm	0.0456 in
20 Gauge	1.01 mm	0.0396 in
21 Gauge	0.93 mm	0.0366 in
22 Gauge	0.85 mm	0.0336 in
23 Gauge	0.78 mm	0.0306 in
24 Gauge	0.70 mm	0.0276 in
25 Gauge	0.63 mm	0.0247 in
26 Gauge	0.55 mm	0.0217 in
27 Gauge	0.51 mm	0.0202 in
28 Gauge	0.48 mm	0.0187 in
29 Gauge	0.44 mm	0.0172 in
30 Gauge	0.40 mm	0.0157 in

Gauge	Thickness (mm)	Thickness (inches)
8 Gauge	4.37 mm	0.1719 in
9 Gauge	3.97 mm	0.1563 in
10 Gauge	3.57 mm	0.1406 in
11 Gauge	3.18 mm	0.1250 in
12 Gauge	2.78 mm	0.1094 in
13 Gauge	2.38 mm	0.0938 in
14 Gauge	1.98 mm	0.0781 in
15 Gauge	1.79 mm	0.0703 in
16 Gauge	1.59 mm	0.0625 in
17 Gauge	1.43 mm	0.0563 in
18 Gauge	1.27 mm	0.0500 in
19 Gauge	1.11 mm	0.0438 in
20 Gauge	0.95 mm	0.0375 in
21 Gauge	0.87 mm	0.0344 in
22 Gauge	0.80 mm	0.0313 in
23 Gauge	0.71 mm	0.0281 in
24 Gauge	0.64 mm	0.0250 in
25 Gauge	0.56 mm	0.0219 in
26 Gauge	0.48 mm	0.0188 in
27 Gauge	0.44 mm	0.0172 in
28 Gauge	0.40 mm	0.0156 in
29 Gauge	0.36 mm	0.0141 in
30 Gauge	0.32 mm	0.0125 in

Gauge	Thickness (mm)	Thickness (inches)
8 Gauge	3.26 mm	0.1285 in
9 Gauge	2.91 mm	0.1144 in
10 Gauge	2.59 mm	0.1019 in
11 Gauge	2.30 mm	0.0907 in
12 Gauge	2.05 mm	0.0808 in
13 Gauge	1.83 mm	0.0720 in
14 Gauge	1.63 mm	0.0641 in
15 Gauge	1.45 mm	0.0571 in
16 Gauge	1.29 mm	0.0508 in
17 Gauge	1.15 mm	0.0453 in
18 Gauge	1.02 mm	0.0403 in
19 Gauge	0.91 mm	0.0359 in
20 Gauge	0.81 mm	0.0320 in
21 Gauge	0.72 mm	0.0285 in
22 Gauge	0.64 mm	0.0253 in
23 Gauge	0.57 mm	0.0226 in
24 Gauge	0.51 mm	0.0201 in
25 Gauge	0.45 mm	0.0179 in
26 Gauge	0.40 mm	0.0159 in
27 Gauge	0.36 mm	0.0142 in
28 Gauge	0.32 mm	0.0126 in
29 Gauge	0.29 mm	0.0113 in
30 Gauge	0.25 mm	0.0100 in

Why Use This Converter

Material Specific Accuracy

Different materials use different gauge systems. Get the correct thickness for Galvanized, Stainless or Aluminum.

Instant Results

Enter a gauge number and receive precise millimeter and inch values in seconds.

Full Reference Charts

Complete thickness tables for every common gauge so you can compare values at a glance.

Professional Grade

Designed for fabricators, engineers, architects and metalworkers who need reliable data.

How It Works

Enter the gauge number (8–30) in the input field.
Select the material: Galvanized Steel, Stainless Steel or Aluminum.
Click Convert. The page updates with a clean URL and accurate result.
View the highlighted row in the full thickness chart below the converter.

Frequently Asked Questions

Gauge systems are material-specific. Galvanized steel follows Manufacturers Standard Gauge (with zinc coating), stainless has its own scale, and aluminum uses the Brown & Sharpe system. The same number therefore represents different actual thicknesses.

Galvanized sheet includes a zinc coating. At the same gauge number, galvanized material is slightly thicker than uncoated carbon steel because of the added zinc layers.

Values shown are nominal thicknesses based on published industry standards. Actual mill production can vary within tolerance ranges. Always verify critical dimensions with a micrometer when precision is required.

This tool covers gauges 8 through 30 — the most commonly used range in fabrication, HVAC, construction and manufacturing.