AWG Wire Gauge Calculator

Convert AWG to wire diameter, cross-section, copper resistance per length, and an estimated current capacity.

Gauge–

Diameter–

Cross-section–

Copper resistance–

Max current (chassis wiring)–

AWG reference table (solid copper, 20 °C)

Diameter, cross-section, and resistance are computed for solid copper at 20 °C; the current column is the standard chassis-wiring ampacity from common wire-ampacity reference tables.

AWG	Ø in	Ø mm	Area mm²	Ω / 1000 ft	Ω / km	Max A (chassis)
0000	0.4600	11.684	107.2	0.04901	0.1608	380
000	0.4096	10.405	85.03	0.0618	0.2028	328
00	0.3648	9.266	67.43	0.07793	0.2557	283
0	0.3249	8.251	53.48	0.09827	0.3224	245
1	0.2893	7.348	42.41	0.1239	0.4065	211
2	0.2576	6.544	33.63	0.1562	0.5126	181
3	0.2294	5.827	26.67	0.197	0.6464	158
4	0.2043	5.189	21.15	0.2484	0.8151	135
5	0.1819	4.621	16.77	0.3133	1.028	118
6	0.1620	4.115	13.3	0.395	1.296	101
7	0.1443	3.665	10.55	0.4981	1.634	89
8	0.1285	3.264	8.366	0.6281	2.061	73
9	0.1144	2.906	6.634	0.7921	2.599	64
10	0.1019	2.588	5.261	0.9988	3.277	55
11	0.0907	2.305	4.172	1.259	4.132	47
12	0.0808	2.053	3.309	1.588	5.21	41
13	0.0720	1.828	2.624	2.003	6.57	35
14	0.0641	1.628	2.081	2.525	8.285	32
15	0.0571	1.450	1.65	3.184	10.45	28
16	0.0508	1.291	1.309	4.015	13.17	22
17	0.0453	1.150	1.038	5.063	16.61	19
18	0.0403	1.024	0.823	6.385	20.95	16
19	0.0359	0.9116	0.6527	8.051	26.41	14
20	0.0320	0.8118	0.5176	10.15	33.31	11
21	0.0285	0.7229	0.4105	12.8	42	9
22	0.0253	0.6438	0.3255	16.14	52.96	7
23	0.0226	0.5733	0.2582	20.35	66.78	4.7
24	0.0201	0.5106	0.2047	25.67	84.21	3.5
25	0.0179	0.4547	0.1624	32.37	106.2	2.7
26	0.0159	0.4049	0.1288	40.81	133.9	2.2
27	0.0142	0.3606	0.1021	51.46	168.8	1.7
28	0.0126	0.3211	0.08098	64.89	212.9	1.4
29	0.0113	0.2859	0.06422	81.83	268.5	1.2
30	0.0100	0.2546	0.05093	103.2	338.5	0.86
31	0.0089	0.2268	0.04039	130.1	426.9	0.7
32	0.0080	0.2019	0.03203	164.1	538.3	0.53
33	0.0071	0.1798	0.0254	206.9	678.8	0.43
34	0.0063	0.1601	0.02014	260.9	855.9	0.33
35	0.0056	0.1426	0.01597	329	1079	0.27
36	0.0050	0.1270	0.01267	414.8	1361	0.21
37	0.0045	0.1131	0.01005	523.1	1716	0.17
38	0.0040	0.1007	0.007967	659.6	2164	0.13
39	0.0035	0.0897	0.006318	831.7	2729	0.11
40	0.0031	0.0799	0.00501	1049	3441	0.09

What the values mean

Conductor diameter — the diameter of the bare solid copper conductor, in inches and millimetres.
Cross section — the conductor's area, which sets its resistance and current capacity.
Ohms per 1000 ft / per km — DC resistance per unit length for copper at 20 °C; it roughly doubles every three gauge steps.
Max A (chassis) — the maximum current for chassis wiring, from standard wire-ampacity reference tables. Real ampacity also depends on insulation, ambient temperature, and bundling, so treat it as a guideline.

AWG wire gauge

diameter = 0.127 mm × 92^((36 − n) / 39)

In the American Wire Gauge system a larger number means a thinner wire, and each 6-gauge step roughly halves (or doubles) the cross-sectional area. Enter an AWG number, or switch to specify a diameter in millimetres to find the nearest gauge and its properties.

Where these ampacities stop applying

The current figures here are for chassis wiring — single conductors in free air, which is the generous case. Power transmission ratings for the same gauge are several times lower, because a conductor in a bundle or a conduit cannot shed heat into open air. Bundling is the factor people miss: a dozen wires carrying their individual ratings inside one loom will all run far hotter than any of them would alone. Insulation temperature rating, ambient temperature, and run length all derate the figure further, and on a long run thevoltage drop usually matters before the heating does.

AWG Wire Gauge Calculator

AWG reference table (solid copper, 20 °C)

What the values mean

AWG wire gauge

Where these ampacities stop applying

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