AWG Wire Gauge Standard Vs. SWG Wire Gauge Standard
American Wire Gauge or AWG is the standard way of measuring wire gauges in the United States. However, in other countries, they use a different standard of measuring, SWG or British Imperial Standard Wire Gauge, for example. The availability of two different standards has led to a difference in how wire gauges are measured and what standard sizes of wire are used.
AWG
AWG is the standard for measuring wire in the United States. This standard is defined by the diameter of the electrical wire that is being measured. Therefore, it is the physical size is what matters most. Also, the larger the physical size of the wire the smaller the wire gauge according to the AWG measurements.
SWG
SWG was the legal standard for measuring wire in the United Kingdom as of 1884. All of the SWG measurements are in metric sizes. In most cases of use of the SWG measuring standard the sizes will be rounded up which does affect the accuracy.
Similarities
In a lot of ways, AWG and SWG standards are similar. Most noteworthy, both standards are based on the physical size of the wire being measured. Also, both share common wire numbers that express those physical sizes. Finally, metal measuring plates are used to determine the size of the wire.
Differences
The most obvious difference is the standard of measurements. AWG is recorded in what is referred to as the imperial system of measurement. This system of measurements is in inches. Therefore, the American standard is different from the SWG system which uses the metric system of measuring. When looking at the charts below there are slight differences in the calculations between the two systems. Especially relevant is the difference that can be seen between the 12 and 24 gauges. These are very common sizes of wire and the chart shows a very drastic difference amongst the size measurements.
Reference charts:
Wire Number | Imperial Standard Wire Gauge | American Wire Gauge |
gauge | ins. dia. | ins. dia. |
0000000 (7/0) | 0.5000 | – |
000000 (6/0) | 0.4640 | 0.580000 |
00000 (5/0) | 0.4320 | 0.516500 |
0000 (4/0) | 0.4000 | 0.460000 |
000 (3/0) | 0.3720 | 0.409642 |
00 (2/0) | 0.3480 | 0.364796 |
0 (1/0) | 0.3240 | 0.324861 |
1 | 0.3000 | 0.289297 |
2 | 0.2760 | 0.257627 |
3 | 0.2520 | 0.229423 |
4 | 0.2320 | 0.2043 |
5 | 0.2120 | 0.1819 |
6 | 0.1920 | 0.1620 |
7 | 0.1760 | 0.1443 |
8 | 0.1600 | 0.1285 |
9 | 0.1440 | 0.1144 |
10 | 0.1280 | 0.1019 |
11 | 0.1160 | 0.0907 |
12 | 0.1040 | 0.0808 |
13 | 0.0920 | 0.0720 |
14 | 0.0800 | 0.0641 |
15 | 0.0720 | 0.0571 |
16 | 0.0640 | 0.0508 |
17 | 0.0560 | 0.0453 |
18 | 0.0480 | 0.0403 |
19 | 0.0400 | 0.0359 |
20 | 0.0360 | 0.0320 |
21 | 0.0320 | 0.0285 |
22 | 0.0280 | 0.0253 |
23 | 0.0240 | 0.0226 |
24 | 0.0220 | 0.0201 |
25 | 0.0200 | 0.0179 |
26 | 0.0180 | 0.0159 |
27 | 0.0164 | 0.0142 |
28 | 0.0148 | 0.0126 |
29 | 0.0136 | 0.0113 |
30 | 0.0124 | 0.0100 |
31 | 0.0116 | 0.0089 |
32 | 0.0108 | 0.0080 |
33 | 0.0100 | 0.0071 |
34 | 0.0092 | 0.0063 |
35 | 0.0084 | 0.0056 |
36 | 0.0076 | 0.0050 |
37 | 0.0068 | 0.0045 |
38 | 0.0060 | 0.0040 |
39 | 0.0052 | 0.0035 |
40 | 0.0048 | 0.0031 |
41 | 0.0044 | 0.0028 |
42 | 0.0040 | 0.0025 |
43 | 0.0036 | 0.0022 |
44 | 0.0032 | 0.0020 |
45 | 0.0028 | 0.0018 |
46 | 0.0024 | 0.0016 |
47 | 0.0020 | 0.0014 |
48 | 0.0016 | 0.0012 |
49 | 0.0012 | 0.0011 |
50 | 0.0010 | 0.0010 |
51 | – | 0.00088 |
52 | – | 0.00078 |
53 | – | 0.00070 |
54 | – | 0.00062 |
55 | – | 0.00055 |
56 | – | 0.00049 |
Wrapping It Up
To learn more about American Wire Gauge measurements check out our blog WHY DO WIRE GAUGE SIZES SEEM TO WORK BACKWARDS?
For additional information on the Wire Harness Assembly Process, please click the links below:
- Wire Harness Manufacturing Terms, Tools, and Tips of the Trade
- Ground Straps: The Official Buyers Resource Guide
You can also receive your own custom wire harness estimate with our Wire Harness Estimator
In addition, click here for an Instant Quote on Braided Ground Straps.
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