Use the chart below to convert standard gauge numbers in decimals of an inch for sheet steel, aluminum and stainless steel.

Gauge #

Sheet Steel

Aluminum

Stainless Steel

1 .2893 (7.3) .2812 (7.1)
 2 .2576 (6.5) .2656 (6.7)
 3 .2391 (6.1) .2294 (5.8) .2500 (6.4)
 4 .2242 (5.7) .2043 (5.2) .2344 (6.0)
 5 .2092 (5.3) .1819 (4.6) .2187 (5.6)
 6 .1943 (4.9) .1620 (4.1) .2031 (5.2)
 7 .1793 (4.6) .1443 (3.7) .1875 (4.8)
 8 .1644 (4.2) .1285 (3.3) .1719 (4.4)
 9 .1495 (3.8) .1144 (2.9) .1562 (4.0)
 10 .1345 (3.4) .1019 (2.6) .1406 (3.6)
 11 .1196 (3.0) .0907 (2.3) .1250 (3.2)
 12 .1046 (2.7) .0808 (2.1) .1094 (2.8)
 13 .0897 (2.3) .0720 (1.8) .0937 (2.4)
 14 .0747 (1.9) .0641 (1.6) .0781 (2.0)
 15 .0673 (1.7) .0571 (1.5) .0703 (1.8)
 16 .0598 (1.5) .0508 (1.3) .0625 (1.6)
 17 .0538 (1.4) .0453 (1.2) .0562 (1.4)
 18 .0478 (1.2) .0403 (1.0) .0500 (1.3)
 19 .0418 (1.1) .0359 (0.9) .0437 (1.1)
 20 .0359 (0.9) .0320 (0.8) .0375 (1.0)
 21 .0329 (0.8) .0285 (0.7) .0344 (0.9)
 22 .0299 (0.8) .0253 (0.6) .0312 (0.8)
 23 .0269 (0.7) .0226 (0.6) .0281 (0.7)
 24 .0239 (0.6) .0201 (0.5) .0250 (0.6)
 25 .0209 (0.6) .0179 (0.5) .0219 (0.6)
 26 .0179 (0.5) .0159 (0.4) .0187 (0.5)
 27 .0164 (0.4) .0142 (0.4) >.0172 (0.4)
 28 .0149 (0.4) .0126 (0.3) .0156 (0.4)
 29 .0135 (0.3) .0113 (0.3) .0141 (0.3)
Dimension in inches (millimeters)