Sheet Metal Gauge Chart
Sheet metal gauge to thickness conversion chart for steel, aluminum, and stainless steel. Shows thickness in both inches and millimeters for each gauge number.
| Gauge | Steel | Aluminum | Stainless | |||
|---|---|---|---|---|---|---|
| in | mm | in | mm | in | mm | |
| 3 | 0.2391 | 6.073 | 0.2294 | 5.827 | 0.2500 | 6.350 |
| 4 | 0.2242 | 5.695 | 0.2043 | 5.189 | 0.2344 | 5.954 |
| 5 | 0.2092 | 5.314 | 0.1819 | 4.620 | 0.2187 | 5.555 |
| 6 | 0.1943 | 4.935 | 0.1620 | 4.115 | 0.2031 | 5.159 |
| 7 | 0.1793 | 4.554 | 0.1443 | 3.665 | 0.1875 | 4.763 |
| 8 | 0.1644 | 4.176 | 0.1285 | 3.264 | 0.1719 | 4.366 |
| 9 | 0.1495 | 3.797 | 0.1144 | 2.906 | 0.1562 | 3.967 |
| 10 | 0.1345 | 3.416 | 0.1019 | 2.588 | 0.1406 | 3.571 |
| 11 | 0.1196 | 3.038 | 0.0907 | 2.304 | 0.1250 | 3.175 |
| 12 | 0.1046 | 2.657 | 0.0808 | 2.052 | 0.1094 | 2.779 |
| 13 | 0.0897 | 2.278 | 0.0720 | 1.829 | 0.0937 | 2.380 |
| 14 | 0.0747 | 1.897 | 0.0641 | 1.628 | 0.0781 | 1.984 |
| 15 | 0.0673 | 1.709 | 0.0571 | 1.450 | 0.0703 | 1.786 |
| 16 | 0.0598 | 1.519 | 0.0508 | 1.290 | 0.0625 | 1.588 |
| 17 | 0.0538 | 1.367 | 0.0453 | 1.151 | 0.0562 | 1.427 |
| 18 | 0.0478 | 1.214 | 0.0403 | 1.024 | 0.0500 | 1.270 |
| 19 | 0.0418 | 1.062 | 0.0359 | 0.912 | 0.0437 | 1.110 |
| 20 | 0.0359 | 0.912 | 0.0320 | 0.813 | 0.0375 | 0.953 |
| 21 | 0.0329 | 0.836 | 0.0285 | 0.724 | 0.0344 | 0.874 |
| 22 | 0.0299 | 0.759 | 0.0253 | 0.643 | 0.0312 | 0.792 |
| 23 | 0.0269 | 0.683 | 0.0226 | 0.574 | 0.0281 | 0.714 |
| 24 | 0.0239 | 0.607 | 0.0201 | 0.511 | 0.0250 | 0.635 |
| 25 | 0.0209 | 0.531 | 0.0179 | 0.455 | 0.0219 | 0.556 |
| 26 | 0.0179 | 0.455 | 0.0159 | 0.404 | 0.0187 | 0.475 |
| 27 | 0.0164 | 0.417 | 0.0142 | 0.361 | 0.0172 | 0.437 |
| 28 | 0.0149 | 0.378 | 0.0126 | 0.320 | 0.0156 | 0.396 |
| 30 | 0.0120 | 0.305 | 0.0100 | 0.254 | 0.0125 | 0.318 |
How to Read This Chart
Find your gauge number in the left column, then look across to the correct metal type column. Each metal has its own gauge standard, so a 16-gauge sheet of steel is a different thickness than 16-gauge aluminum. The gauge number is inversely related to thickness — lower gauge numbers are thicker.
Frequently Asked Questions
What does sheet metal gauge mean?
Sheet metal gauge is a standardized numbering system indicating the thickness of sheet metal. A higher gauge number means thinner metal. For example, 10-gauge steel is 0.1345 inches thick, while 20-gauge steel is only 0.0359 inches thick.
Is sheet metal gauge the same for all metals?
No. The same gauge number corresponds to different thicknesses depending on the metal. For example, 16-gauge steel is 0.0598 inches, 16-gauge aluminum is 0.0508 inches, and 16-gauge stainless steel is 0.0625 inches. Always verify using the correct column for your metal type.
What gauge sheet metal is used for car body panels?
Most automotive body panels use 18 to 20 gauge steel (0.0359 to 0.0478 inches). Structural components like floor pans may use thicker 16-gauge steel. Modern cars increasingly use thinner, high-strength steel or aluminum panels.
How do I measure sheet metal gauge?
Use a sheet metal gauge tool (a round disc with notches) or a micrometer/caliper to measure thickness directly. Compare the measurement to this chart to determine the gauge number. Digital calipers provide the most accurate readings.