Values presented here are standards available for many independent publications, but
ultimately they all originate from the American Wire Gauge (AWG) system (also aka the
Brown and Sharp gauge). It has been in existence since the mid 1800s in the U.S. and
Canada.
Note that as wire gauge number is increased the wire diameter decreases. Although
it might seem somewhat backward, there is a good reason for it. Originally, it was related
to the number of time a wire needed to be drawn through an extraction die in order to
achieve the final wire size.
By definition, 36 AWG is 0.0050 inches in diameter, and 0000 (four-ought) is 0.4600
inches in diameter. The ratio of these diameters is 92, and there are 40 gauge sizes
from #36 to #0000, or 39 steps. Using this ratio, wire gauge sizes vary geometrically
according to the following formula: The diameter of a 36 AWG wire is:

Accordingly, the ASTM B 258-02
standard defines the ratio between successive sizes to be the 39th root of 92, or approximately
1.1229322.

Stranding designation of a/b means a number of b gauge wires. E.g., 7/44 means 7 strands
of 44 AWG solid wire.
Note: Just a 3 dB change in power represents a doubling (or halving) of power, a change
of 3 wire sizes represents approximately a doubling (or halving) of cross-sectional area.
See wire gauge conversion chart at bottom of page. Values given at 25 °C, and are
based on ideal parameters of pure copper.
A circular mil is the cross-sectional area of a circle with a diameter of 1 mil
(1/000th of an inch).
40 |
0.003145 |
0.07988 |
9.888 |
0.0299 |
0.0445 |
1049 |
3442 |
0.09 |
39 |
0.003531 |
0.08969 |
12.47 |
0.0377 |
0.0562 |
832 |
2729 |
0.11 |
38 |
0.003965 |
0.1007 |
15.72 |
0.0476 |
0.0708 |
660 |
2164 |
0.13 |
37 |
0.004453 |
0.1131 |
19.83 |
0.0600 |
0.0893 |
523 |
1716 |
0.17 |
36 |
0.005000 |
0.1270 |
25.00 |
0.0757 |
0.113 |
415 |
1361 |
0.21 |
35 |
0.005614 |
0.1426 |
31.52 |
0.0954 |
0.142 |
329 |
1079 |
0.27 |
34 |
0.006304 |
0.1601 |
39.75 |
0.120 |
0.179 |
261 |
856 |
0.33 |
33 |
0.007080 |
0.1798 |
50.13 |
0.152 |
0.226 |
207 |
679 |
0.43 |
32 |
0.007950 |
0.2019 |
63.21 |
0.191 |
0.285 |
164 |
538 |
0.53 |
31 |
0.007950 |
0.2268 |
79.70 |
0.241 |
0.359 |
130 |
427 |
0.7 |
30 |
0.01003 |
0.2548 |
100.5 |
0.304 |
0.453 |
103 |
339 |
0.86 |
29 |
0.01126 |
0.2860 |
126.7 |
0.384 |
0.571 |
81.8 |
268 |
1.2 |
28 |
0.01246 |
0.3211 |
159.8 |
0.484 |
0.720 |
64.8 |
213 |
1.4 |
27 |
0.01419 |
0.3604 |
201.5 |
0.610 |
0.908 |
51.5 |
169 |
1.7 |
26 |
0.01594 |
0.4049 |
254.1 |
0.769 |
1.14 |
40.8 |
134 |
2.2 |
25 |
0.01790 |
0.4547 |
320.4 |
0.970 |
1.44 |
32.4 |
106 |
2.7 |
24 |
0.02010 |
0.5105 |
404.0 |
1.22 |
1.82 |
25.7 |
84.2 |
3.5 |
23 |
0.02257 |
0.5733 |
509.5 |
1.54 |
2.29 |
20.4 |
66.8 |
4.7 |
22 |
0.02535 |
0.6439 |
642.4 |
1.95 |
2.89 |
16.1 |
53.0 |
7 |
21 |
0.02846 |
0.7229 |
810.1 |
2.45 |
3.65 |
12.8 |
42.0 |
9 |
20 |
0.03196 |
0.8118 |
1022 |
3.09 |
4.60 |
10.2 |
33.3 |
11 |
19 |
0.03589 |
0.9116 |
1288 |
3.90 |
5.80 |
8.05 |
26.4 |
14 |
18 |
0.0403 |
1.024 |
1624 |
4.92 |
7.32 |
6.39 |
20.9 |
16 |
17 |
0.04526 |
1.150 |
2048 |
6.20 |
9.23 |
5.06 |
16.6 |
19 |
16 |
0.05082 |
1.291 |
2583 |
7.82 |
11.6 |
4.02 |
13.2 |
22 |
15 |
0.05707 |
1.450 |
3257 |
9.86 |
14.7 |
3.18 |
10.4 |
28 |
14 |
0.06408 |
1.628 |
4107 |
12.4 |
18.5 |
2.53 |
8.28 |
32 |
13 |
0.07196 |
1.828 |
5178 |
15.7 |
23.3 |
2.00 |
6.57 |
35 |
12 |
0.08081 |
2.053 |
6530 |
19.8 |
29.4 |
1.59 |
5.21 |
41 |
11 |
0.09074 |
2.305 |
8234 |
24.9 |
37.1 |
1.26 |
4.13 |
47 |
10 |
0.1019 |
2.588 |
10380 |
31.4 |
46.8 |
0.999 |
3.28 |
55 |
9 |
0.1144 |
2.906 |
13090 |
39.6 |
59.0 |
0.792 |
2.60 |
64 |
8 |
0.1285 |
3.264 |
16510 |
50.0 |
74.4 |
0.628 |
2.06 |
73 |
7 |
0.1443 |
3.665 |
20820 |
63.0 |
93.8 |
0.498 |
1.63 |
89 |
6 |
0.1620 |
4.115 |
26250 |
79.5 |
118 |
0.395 |
1.30 |
101 |
5 |
0.1819 |
4.620 |
33100 |
100 |
149 |
0.313 |
1.03 |
118 |
4 |
0.2043 |
5.189 |
41740 |
126 |
188 |
0.249 |
0.815 |
135 |
3 |
0.2294 |
5.827 |
52640 |
159 |
237 |
0.197 |
0.646 |
158 |
2 |
0.2576 |
6.543 |
66370 |
201 |
299 |
0.156 |
0.512 |
181 |
1 |
0.2893 |
7.348 |
83690 |
253 |
377 |
0.124 |
0.407 |
211 |
0 |
0.3249 |
8.252 |
105500 |
320 |
475 |
0.098 |
0.323 |
328 |
00 |
0.3648 |
9.266 |
133100 |
403 |
599 |
0.078 |
0.256 |
283 |
000 |
0.4096 |
10.40 |
167800 |
508 |
756 |
0.062 |
0.203 |
245 |
0000 |
0.4600 |
11.68 |
211600 |
641 |
953 |
0.049 |
0.161 |
Wire Gauge Conversions to Diameter in Inches
All Units Are in Inches
7/0 |
0.6513 |
0.490 |
0.500 |
|
0.5000 |
6/0 |
0.5800 |
0.460 |
0.464 |
|
0.4688 |
5/0 |
0.5165 |
0.430 |
0.432 |
|
0.4375 |
4/0 |
0.4600 |
0.3938 |
0.400 |
0.454 |
0.4063 |
3/0 |
0.4096 |
0.3625 |
0.372 |
0.425 |
0.3750 |
2/0 |
0.3648 |
0.3310 |
0.348 |
0.380 |
0.3438 |
1/0 |
0.3249 |
0.3065 |
0.324 |
0.340 |
0.3125 |
1 |
0.2893 |
0.2830 |
0.300 |
0.300 |
0.2813 |
2 |
0.2576 |
0.2625 |
0.276 |
0.284 |
0.2656 |
3 |
0.2294 |
0.2437 |
0.252 |
0.259 |
0.2391 |
4 |
0.2043 |
0.2253 |
0.232 |
0.238 |
0.2242 |
5 |
0.1819 |
0.2070 |
0.212 |
0.220 |
0.2092 |
6 |
0.1620 |
0.1920 |
0.192 |
0.203 |
0.1943 |
7 |
0.1443 |
0.1770 |
0.176 |
0.180 |
0.1793 |
8 |
0.1285 |
0.1620 |
0.160 |
0.165 |
0.1644 |
9 |
0.1144 |
0.1483 |
0.144 |
0.148 |
0.1495 |
10 |
0.1019 |
0.1350 |
0.128 |
0.134 |
0.1345 |
11 |
0.0907 |
0.1205 |
0.116 |
0.120 |
0.1196 |
12 |
0.0808 |
0.1055 |
0.104 |
0.109 |
0.1046 |
13 |
0.0719 |
0.0915 |
0.092 |
0.095 |
0.0897 |
14 |
0.0641 |
0.0800 |
0.080 |
0.083 |
0.0747 |
15 |
0.0571 |
0.0720 |
0.072 |
0.072 |
0.0673 |
16 |
0.0508 |
0.0625 |
0.064 |
0.065 |
0.0598 |
17 |
0.04526 |
0.054 |
0.056 |
0.058 |
0.0538 |
18 |
0.04030 |
0.0475 |
0.048 |
0.049 |
0.0478 |
19 |
0.03589 |
0.0410 |
0.040 |
0.042 |
0.0418 |
20 |
0.03196 |
0.0348 |
0.036 |
0.035 |
0.0359 |
21 |
0.02846 |
0.03175 |
0.032 |
0.032 |
0.0329 |
22 |
0.02535 |
0.0286 |
0.028 |
0.028 |
0.0299 |
23 |
0.02257 |
0.0258 |
0.024 |
0.025 |
0.0269 |
24 |
0.02010 |
0.0230 |
0.022 |
0.022 |
0.0239 |
25 |
0.01790 |
0.0204 |
0.020 |
0.020 |
0.0209 |
26 |
0.01594 |
0.0181 |
0.018 |
0.018 |
0.0179 |
27 |
0.01420 |
0.0173 |
0.0164 |
0.016 |
0.0164 |
28 |
0.01264 |
0.0162 |
0.0148 |
0.014 |
0.0149 |
29 |
0.01126 |
0.0150 |
0.0136 |
0.013 |
0.0135 |
30 |
0.0103 |
0.014 |
0.0124 |
0.012 |
0.0120 |
31 |
0.00893 |
0.0132 |
0.0116 |
0.010 |
0.0109 |
32 |
0.00795 |
0.0128 |
0.0108 |
0.009 |
0.0102 |
33 |
0.00708 |
0.0118 |
0.0100 |
0.008 |
0.0094 |
34 |
0.00630 |
0.0104 |
0.0092 |
0.007 |
0.0086 |
35 |
0.00561 |
0.0095 |
0.0084 |
0.005 |
0.0078 |
36 |
0.00500 |
0.0090 |
0.0076 |
0.004 |
0.0070 |
37 |
0.00445 |
0.0085 |
0.0068 |
|
|
38 |
0.00396 |
0.0080 |
0.0060 |
|
|
39 |
0.00353 |
0.0075 |
0.0052 |
|
|
40 |
0.00314 |
0.007 |
0.0048 |
|
|
41 |
0.00279 |
0.0066 |
0.0044 |
|
|
42 |
0.00249 |
0.0062 |
0.0040 |
|
|
43 |
0.00221 |
0.0060 |
0.0036 |
|
|
44 |
0.00198 |
0.0058 |
0.0032 |
|
|
45 |
0.00176 |
0.0055 |
0.0028 |
|
|
46 |
0.00157 |
0.0052 |
0.0024 |
|
|
47 |
0.00140 |
0.0050 |
0.0016 |
|
|
48 |
0.00124 |
0.0048 |
0.0012 |
|
|
49 |
0.00111 |
0.0046 |
0.0010 |
|
|
50 |
0.00099 |
0.0044 |
|
|
|
51 |
0.00088 |
|
|
|
|
52 |
0.00078 |
|
|
|
|
53 |
0.00070 |
|
|
|
|
54 |
0.00060 |
|
|
|
|
55 |
0.00050 |
|
|
|
|
56 |
0.00040 |
|
|
|
|
- AWG = American Wire Gauge (Brown & Sharpe)
- W & M = Washburn & Moen (steel wire gauge)
- SWG = Imperial Standard Wire Gauge
- BWG = Birmingham or Stubs Wire Gauge
- US Standard = United States Standard (Revised)
|
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