AWG Cable Grade Gauge

What is American Wire Gauge (AWG)?

American Wire Gauge (AWG Cable) is the standard way to denote wire size in North America. In AWG cable, the larger the number, the smaller the wire diameter and thickness. The largest standard size is 0000 AWG, and 40 AWG Cable is the smallest standard size. It may also be called Brown & Sharpe wire gauge or simply the gauge of the wire.

AWG is for single-strand, solid, round, electrically conductive wire. It was first introduced in 1857 as a standard to replace the various measurements used by different manufacturers. Use of larger numbers denoting smaller wires is similar to Standard Wire Gauge, which is used in Britain. Most other countries use an international metric standard of wire cross-section in square millimeters (mm²) defined in International Electrotechnical Commission 60228.

AWG cable size does not include the size of the insulation protecting a wire.

0000 AWG cable is defined as 0.46 inches in diameter, and 36 AWG cable is defined as 0.005 inches in diameter. All other sizes are derived as logarithmic steps between these two defined sizes. There are 39 gauge steps between these sizes, and the ratio is 1-to-92 in diameter. Therefore, each AWG step is the 39th root of 92, or approximately 1.12293 times the change in diameter.

A smaller gauge (larger size) wire can safely conduct more electricity than a larger gauge (smaller size) wire. Decreasing the AWG cable size of a wire by three will double the cross-sectional area of a wire and double the amount of current it can carry. Changing the AWG cable size by 10 will change the cross-section by tenfold.

American Conductor Stranding – AWG Table

AWG (Americal Wire Gauge) = Actual Cross Section in mm² and Conductor Resistance

AWG cable is shown below with its exact equivalent value in mm² and diameter (mm).

AWG Number	Cable Cross Section in mm²	Outer Diameter Ø mm	Conductor Resistance in Ohm/km
1000 MCM	507	29,3	0,036
900	456	27,8	0,04
750	380	25,4	0,048
600	304	22,7	0,061
550	279	21,7	0,066
500	253	20,7	0,07
450	228	19,6	0,08
400	203	18,5	0,09
350	177	17,3	0,10
300	152	16,0	0,12
250	127	14,6	0,14
4/0	107,2	11,68	0,18
3/0	85,0	10,40	0,23
2/0	67,4	9,27	0,29
0	53,4	8,25	0,37
1	42,4	7,35	0,47
2	33,6	6,54	0,57
3	26,7	5,83	0,71
4	21,2	5,19	0,91
5	16,8	4,62	1,12
6	13,3	4,11	1,44
7	10,6	3,67	1,78
8	8,34	3,26	2,36
9	6,62	2,91	2,77
10	5,26	2,59	3,64
11	4,15	2,30	4,44
12	3,31	2,05	5,41
13	2,63	1,83	7,02
14	2,08	1,63	8,79
15	1,65	1,45	11,2
16	1,31	1,29	14,7
17	1,04	1,15	17,8
18	0,8230	1,0240	23,0
19	0,6530	0,9120	28,3
20	0,5190	0,8120	34,5
21	0,4120	0,7230	44,0
22	0,3240	0,6440	54,8
23	0,2590	0,5730	70,1
24	0,2050	0,5110	89,2
25	0,1630	0,4550	111,0
26	0,1280	0,4050	146,0
27	0,1020	0,3610	176,0
28	0,0804	0,3210	232,0
29	0,0646	0,2860	282,0
30	0,0503	0,2550	350,0
31	0,0400	0,2270	446,0
32	0,0320	0,2020	578,0
33	0,0252	0,1800	710,0
34	0,0200	0,1600	899,0
35	0,0161	0,1430	1125,0
36	0,0123	0,1270	1426,0
37	0,0100	0,1130	1800,0
38	0,00795	0,1010	2255,0
39	0,00632	0,0897	2860,0

4/0 is also known as 0000; 1 mil = inch = 0,0254 mm
*shown in MCM (circular mills) for bigger cross sections

1 CM = 1 Circ. mil = 0,0005067 mm²
1 MCM = 1000 Circ. mils = 0,5067 mm²

UL/CSA current-carrying capacity for flexible cables

Hook-up wire at ambient temperature up to 30°C

AWG	Cross Section in mm²	Current-Carrying Capacity in Ampere
24	0,21	3,5 A
22	0,33	5,0 A
20	0,52	6,0 A
18	0,82	9,5 A
16	1,31	20 A
14	2,08	24 A
12	3,32	34 A
10	5,26	52 A
8	8,35	75 A
6	13,29	95 A
4	21,14	120 A
3	26,65	154 A
2	33,61	170 A
1	42,38	180 A

Correction-factors at ambient temperature over 30°C

For temperatures over 30°C, multiply the current-carrying capacity in the tables times correction-factor (f) to obtain the allowable current.

Ambient Temperature °C	Correction-Factor (f)
31-35	0,91
36-40	0,82
41-45	0,71
46-50	0,58

Multi conductor AWG cable at ambient temperature up to 30°C

AWG Cable Number	Cross Section in mm²	Current-Carrying Capacity in Ampere (Number of Cores)
		up to 3	4 – 6	7 – 24	25 – 42	43 and above
24	0,21	2	1,6	1,4	1,2	1,0
22	0,33	3	2,4	2,1	1,8	1,5
20	0,52	5	4,0	3,5	3,0	2,5
18	0,82	7	5,6	4,9	4,2	3,5
16	1,31	10	8,0	7,0	6,0	5,0
14	2,08	15	12,0	10,5	9,0	7,5
12	3,32	20	16,0	14,0	12,0	10,0
10	5,26	30	24	21	18	15
8	8,35	40	32	28	24	20
6	13,29	55	44	38	33	27
4	21,14	70	56	49	42	35
3	26,65	80	64	56	48	40
2	33,61	95	76	66	57	47
1	42,38	110	88	77	66	55

The most common method of referring to conductor sizes uses the cross-sectional area, expressed in mm². The following AWG metric conversion table converts AWG to mm and inches, and also lists the cross sectional area (mm²).

AWG CABLE METRIC CONVERSION CHART (AWG TO MM)

American Wire Gauge (AWG)	Diameter (in)	Diameter (mm)	Cross sectional area (mm²)
0000 (4/0)	0.460	11.7	107.0
000 (3/0)	0.410	10.4	85.0
00 (2/0)	0.365	9.27	67.4
0 (1/0)	0.325	8.25	53.5
1	0.289	7.35	42.4
2	0.258	6.54	33.6
3	0.229	5.83	26.7
4	0.204	5.19	21.1
5	0.182	4.62	16.8
6	0.162	4.11	13.3
7	0.144	3.67	10.6
8	0.129	3.26	8.36
9	0.114	2.91	6.63
10	0.102	2.59	5.26
11	0.0.907	2.30	4.17
12	0.0808	2.05	3.31
13	0.0720	1.83	2.63
14	0.0641	1.63	2.08
15	0.0571	1.45	1.65
16	0.0508	1.29	1.31
17	0.0453	1.15	1.04
18	0.0403	1.02	0.82
19	0.0359	0.91	0.65
20	0.0320	0.81	0.52
21	0.0285	0.72	0.41
22	0.0254	0.65	0.33
23	0.0226	0.57	0.26
24	0.0201	0.51	0.20
25	0.0179	0.45	0.16
26	0.0159	0.40	0.13