Formulas

Sheetmetal Gauge Conversion Chart

Gauge No. Steel Stainless Steel Aluminum
7 179
8 .164 .172
9 .150 .156
10 .135 .141
11 .120 .125
12 .105 .109
13 .090 .094 .072
14 .075 .078 .064
15 .067 .070 .057
16 .060 .063 .051
17 .054 .056 .045
18 .048 .050 .040
19 .042 .044 .036
20 .036 .038 .032
21 .033 .034 .028
22 .030 .031 .025
23 .027 .028 .023
24 .024 .025 .020
25 .021 .022 .018
26 .018 .019 .017
27 .016 .017 .014
28 .015 .016
29 .014 .014
30 .012 .013
31 .011

Metric/Inch Conversion Chart

Millimeters Fractions Inches
.397 1/64 .015625
.794 1/32 .03125
1.191 3/64 .046875
1.588 1/16 .0625
1.984 5/64 .078125
2.381 3/32 .09375
2.778 7/64 .109375
3.175 1/8 .125
3.572 9/64 .140625
3.969 5/32 .15625
4.366 11/64 .171875
4.762 3/16 .1875
5.159 13/64 .203125
5.556 7/32 .21875
5.953 15/64 .234375
6.350 1/4 .25
6.747 17/64 .265625
7.144 9/32 .28125
7.541 19/64 .296875
7.938 5/16 .3125
8.334 21/64 .328125
8.731 11/32 .34375
9.128 23/64 .359375
9.525 3/8 .375
9.922 25/64 .390625
Millimeters Fractions Inches
13.097 33/64 .515625
13.494 17/32 .53125
13.891 35/64 .546875
14.288 9/16 .5625
14.684 37/64 .573125
15.081 19/32 .59375
15.478 39/64 .609375
15.875 5/8 .625
16.272 41/64 .640625
16.669 21/32 .65625
17.066 43/64 .671875
17.462 11/16 .6875
17.859 45/64 .703125
18.256 23/32 .71875
18.653 47/64 .734375
19.050 3/4 .75
19.447 49/64 .765625
19.844 25/32 .78125
20.241 51/64 .796875
20.638 13/16 .8125
21.034 53/64 .828125
21.431 27/32 .84375
21.828 55/64 .859375
22.225 7/8 .875
22.622 57/64 .890625