Conversion Metrics

Metric and Imperial

1″ = 25.4mm Easy!

Imperial(Inches) mm
0.001″ (1 thou.) 0.0254
1/16″ 1.5875
1/8″ 3.175
3/16″ 4.7625
1/4″ 6.35
3/8″ 9.525
1/2″ 12.7
5/8″ 15.875
3/4″ 19.05
1″ 25.4
1 1/4″ 31.75
1 1/2″ 38.1
2″ 50.8

SWG and Metric

Standard Wire Gauge is an old British standard which is still used today, although it is mainly used for metal thickness, for example the thickness of a sheet of metal or the thickness of the wall of a tube. SWG is no longer popular for wire sizes, instead cross-sectional area is now a more popular measurement – usually expressed in mm^2.

SWG mm SWG mm SWG mm SWG mm
1 7.6200 14 2.0320 27 0.4166 40 0.1219
2 7.0104 15 1.8288 28 0.3759 41 0.1118
3 6.4008 16 1.6256 29 0.3454 42 0.1016
4 5.8928 17 1.4224 30 0.3150 43 0.0914
5 5.3848 18 1.2192 31 0.2946 44 0.0813
6 4.8768 19 1.0160 32 0.2743 45 0.0711
7 4.4704 20 0.9144 33 0.2540 46 0.0610
8 4.0640 21 0.8128 34 0.2337 47 0.0580
9 3.6576 22 0.7112 35 0.2134 48 0.0406
10 3.2512 23 0.6096 36 0.1930 49 0.0305
11 2.9464 24 0.5588 37 0.1727 50 0.0254
12 2.6416 25 0.5080 38 0.1524
13 2.2368 26 0.4572 39 0.1321

AWG and metric

American Wire Gauge is still used as a wire diameter and is usually stated along with a metric mm^2 for the size of a wire.

AWG Diameter(mm) Area(mm^2)
2 6.544 33.6
4 5.189 21.2
6 4.115 13.3
8 3.264 8.37
10 2.588 5.26
12 2.053 3.31
14 1.628 2.08
16 1.291 1.31
18 1.024 0.823
20 0.812 0.518
22 0.644 0.326
24 0.511 0.205
26 0.405 0.129
28 0.321 0.0810

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