MM to Gauge Conversion

[Christopher]

I thought this might be useful as I had to use it today

Wire cross sectional area calculation

The n gauge wire's cross sercional area An in square millimeters (mm2) is equal to pi divided by 4 times the square wire diameter d in millimeters (mm):

An (mm2) = (π/4)×dn2

SWG to mm conversion chart

SWG #	Diameter (mm)	Area (mm2)
7/0	12.700	126.6769
6/0	11.786	109.0921
5/0	10.973	94.5638
4/0	10.160	81.0732
3/0	9.449	70.1202
2/0	8.839	61.3643
0	8.230	53.1921
1	7.620	45.6037
2	7.010	38.5989
3	6.401	32.1780
4	5.893	27.2730
5	5.385	22.7735
6	4.877	18.6793
7	4.470	15.6958
8	4.064	12.9717
9	3.658	10.5071
10	3.251	8.3019
11	2.946	6.8183
12	2.642	5.4805
13	2.337	4.2888
14	2.032	3.2429
15	1.829	2.6268
16	1.626	2.0755
17	1.422	1.5890
18	1.219	1.1675
19	1.016	0.8107
20	0.914	0.6567
21	0.813	0.5189
22	0.711	0.3973
23	0.610	0.2919
24	0.559	0.2452
25	0.5080	0.2027
26	0.4572	0.1642
27	0.4166	0.1363
28	0.3759	0.1110
29	0.3454	0.0937
30	0.3150	0.0779
31	0.2946	0.0682
32	0.2743	0.0591
33	0.2540	0.0507
34	0.2337	0.0429
35	0.2134	0.0358
36	0.1930	0.0293
37	0.1727	0.0234
38	0.1524	0.0182
39	0.1321	0.0137
40	0.1219	0.0117
41	0.1118	0.0098
42	0.1016	0.0081
43	0.0914	0.0066
44	0.0813	0.0052
45	0.0711	0.0040
46	0.0610	0.0029
47	0.0508	0.0020
48	0.0406	0.0013
49	0.0305	0.0007
50	0.0254	0.0005