What are the differences between BWG and SWG?

Tuesday November 7th, 2023 | Francesco Grillo | Expertise

The Birmingham Wire Gauge (BWG) and the Standard Wire Gauge (SWG) are two different systems for measuring the thickness or diameter of wire. Here’s a comparison chart that shows the wire sizes in both BWG and SWG, along with their corresponding diameters in inches and millimeters:

BWG SWG Diameter (inches) Diameter (mm)
0000 0 0.454 11.58
000 1 0.425 10.79
00 2 0.380 9.65
0 3 0.340 8.61
1 4 0.300 7.62
2 5 0.269 6.86
3 6 0.239 6.07
4 7 0.224 5.69
5 8 0.207 5.26
6 9 0.192 4.88
7 10 0.177 4.50
8 11 0.162 4.12
9 12 0.148 3.76
10 13 0.134 3.40
11 14 0.120 3.05
12 15 0.105 2.67
13 16 0.091 2.31
14 17 0.080 2.03
15 18 0.072 1.83
16 19 0.065 1.65
17 20 0.058 1.47
18 21 0.049 1.24
19 22 0.042 1.07
20 23 0.035 0.89
21 24 0.032 0.81
22 25 0.028 0.71
23 26 0.025 0.64
24 27 0.022 0.56
25 28 0.020 0.51
26 29 0.018 0.46
27 30 0.016 0.41
28 31 0.014 0.36
29 32 0.013 0.33
30 33 0.012 0.30

Please note that there may be slight variations in wire gauge standards depending on the industry and region, so it’s important to double-check the specific standards and requirements for your application.