Wire Gauge and Current Limits Including Skin Depth and Tensile Strength (2024)


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AWG Wire Sizes (see chart below)

AWG: In the American Wire Gauge (AWG) system, wire size diameters can be calculated by applying the formula D(AWG)=.005·92^{((36-AWG)/39)} inch. For the 00, 000, 0000 etc. gauges you use -1, -2, -3, which makes more sense mathematically than "double nought." This means that in American wire gage every 6 gauge decrease gives a doubling of the wire diameter, and every 3 gauge decrease doubles the wire cross sectional area. Similar to dB in signal and power levels. An approximate but accurate enough form of this formula contributed by Mario Rodriguez is D = .460 * (57/64)^{(awg +3)} or D = .460 * (0.890625)^{(awg +3)}.

Metric Wire Gauges (see table below)

Metric Gauge:In the Metric Gauge scale, the gauge is 10 times the diameter in millimeters,so a 50 gauge metric wire would be 5 mm in diameter. Note that in AWG thediameter goes up as the gauge goes down, but for metric gauges it is theopposite. Probably because of this confusion, most of the time metric sizedwire is specified in millimeters rather than metric gauges.

Load Carrying Capacities (see table below)

Definition: ampacity is the current carryingcapability of a wire. In other words, how many amps can it transmit? Thefollowing chart is a guideline of ampacity or copper wire current carryingcapacity following the Handbook of Electronic Tables and Formulas forAmerican Wire Gauge. As you might guess, the rated ampacities are just arule of thumb. In careful engineering the voltage drop, insulationtemperature limit, thickness, thermal conductivity, and air convection andtemperature should all be taken into account. The Maximum Amps for PowerTransmission uses the 700 circular mils per amp rule, which is very veryconservative. The Maximum Amps for Chassis Wiring is also a conservativerating, but is meant for wiring in air, and not in a bundle. For short lengthsof wire, such as is used in battery packs you should trade off the resistanceand load with size, weight, and flexibility. NOTE: For installations that needto conform to the National Electrical Code, you must use their guidelines.Contact your local electrician to find out what is legal!

Maximum Frequency for 100% Skin Depth Chart

This data isuseful for high frequency AC engineering. When high frequency AC is conductedby a wire there is a tendency for the current to flow along the outside of thewire. This increases the effective resistance. The frequency listed in thetable shows the frequency at which the calculated skin depth is equal to theradius of the wire, and is an indication that above this frequency you shouldstart considering the skin effect when calculating the wire's resistance.

Breaking Force for Copper Wire

This estimate is based on nick-free soft annealed Cu wire having a tensile strength of 37000 pounds per square inch.

AWG gauge	Conductor Diameter Inches	Conductor Diameter mm	Conductor cross section in mm²	Ohms per 1000 ft.	Ohms per km	Maximum amps for chassis wiring	Maximum amps for power transmission	Maximum frequency for 100% skin depth for solid conductor copper	Breaking force Soft Annealed Cu 37000 PSI
0000	0.46	11.684	107	0.049	0.16072	380	302	125 Hz	6120 lbs
000	0.4096	10.40384	84.9	0.0618	0.202704	328	239	160 Hz	4860 lbs
00	0.3648	9.26592	67.4	0.0779	0.255512	283	190	200 Hz	3860 lbs
0	0.3249	8.25246	53.5	0.0983	0.322424	245	150	250 Hz	3060 lbs
1	0.2893	7.34822	42.4	0.1239	0.406392	211	119	325 Hz	2430 lbs
2	0.2576	6.54304	33.6	0.1563	0.512664	181	94	410 Hz	1930 lbs
3	0.2294	5.82676	26.7	0.197	0.64616	158	75	500 Hz	1530 lbs
4	0.2043	5.18922	21.1	0.2485	0.81508	135	60	650 Hz	1210 lbs
5	0.1819	4.62026	16.8	0.3133	1.027624	118	47	810 Hz	960 lbs
6	0.162	4.1148	13.3	0.3951	1.295928	101	37	1100 Hz	760 lbs
7	0.1443	3.66522	10.6	0.4982	1.634096	89	30	1300 Hz	605 lbs
8	0.1285	3.2639	8.37	0.6282	2.060496	73	24	1650 Hz	480 lbs
9	0.1144	2.90576	6.63	0.7921	2.598088	64	19	2050 Hz	380 lbs
10	0.1019	2.58826	5.26	0.9989	3.276392	55	15	2600 Hz	314 lbs
11	0.0907	2.30378	4.17	1.26	4.1328	47	12	3200 Hz	249 lbs
12	0.0808	2.05232	3.31	1.588	5.20864	41	9.3	4150 Hz	197 lbs
13	0.072	1.8288	2.63	2.003	6.56984	35	7.4	5300 Hz	150 lbs
14	0.0641	1.62814	2.08	2.525	8.282	32	5.9	6700 Hz	119 lbs
15	0.0571	1.45034	1.65	3.184	10.44352	28	4.7	8250 Hz	94 lbs
16	0.0508	1.29032	1.31	4.016	13.17248	22	3.7	11 k Hz	75 lbs
17	0.0453	1.15062	1.04	5.064	16.60992	19	2.9	13 k Hz	59 lbs
18	0.0403	1.02362	0.823	6.385	20.9428	16	2.3	17 kHz	47 lbs
19	0.0359	0.91186	0.653	8.051	26.40728	14	1.8	21 kHz	37 lbs
20	0.032	0.8128	0.519	10.15	33.292	11	1.5	27 kHz	29 lbs
21	0.0285	0.7239	0.412	12.8	41.984	9	1.2	33 kHz	23 lbs
22	0.0253	0.64516	0.327	16.14	52.9392	7	0.92	42 kHz	18 lbs
23	0.0226	0.57404	0.259	20.36	66.7808	4.7	0.729	53 kHz	14.5 lbs
24	0.0201	0.51054	0.205	25.67	84.1976	3.5	0.577	68 kHz	11.5 lbs
25	0.0179	0.45466	0.162	32.37	106.1736	2.7	0.457	85 kHz	9 lbs
26	0.0159	0.40386	0.128	40.81	133.8568	2.2	0.361	107 kHz	7.2 lbs
27	0.0142	0.36068	0.102	51.47	168.8216	1.7	0.288	130 kHz	5.5 lbs
28	0.0126	0.32004	0.080	64.9	212.872	1.4	0.226	170 kHz	4.5 lbs
29	0.0113	0.28702	0.0647	81.83	268.4024	1.2	0.182	210 kHz	3.6 lbs
30	0.01	0.254	0.0507	103.2	338.496	0.86	0.142	270 kHz	2.75 lbs
31	0.0089	0.22606	0.0401	130.1	426.728	0.7	0.113	340 kHz	2.25 lbs
32	0.008	0.2032	0.0324	164.1	538.248	0.53	0.091	430 kHz	1.8 lbs
Metric 2.0	0.00787	0.200	0.0314	169.39	555.61	0.51	0.088	440 kHz
33	0.0071	0.18034	0.0255	206.9	678.632	0.43	0.072	540 kHz	1.3 lbs
Metric 1.8	0.00709	0.180	0.0254	207.5	680.55	0.43	0.072	540 kHz
34	0.0063	0.16002	0.0201	260.9	855.752	0.33	0.056	690 kHz	1.1 lbs
Metric 1.6	0.0063	0.16002	0.0201	260.9	855.752	0.33	0.056	690 kHz
35	0.0056	0.14224	0.0159	329	1079.12	0.27	0.044	870 kHz	0.92 lbs
Metric 1.4	.00551	.140	0.0154	339	1114	0.26	0.043	900 kHz
36	0.005	0.127	0.0127	414.8	1360	0.21	0.035	1100 kHz	0.72 lbs
Metric 1.25	.00492	0.125	0.0123	428.2	1404	0.20	0.034	1150 kHz
37	0.0045	0.1143	0.0103	523.1	1715	0.17	0.0289	1350 kHz	0.57 lbs
Metric 1.12	.00441	0.112	0.00985	533.8	1750	0.163	0.0277	1400 kHz
38	0.004	0.1016	0.00811	659.6	2163	0.13	0.0228	1750 kHz	0.45 lbs
Metric 1	.00394	0.1000	0.00785	670.2	2198	0.126	0.0225	1750 kHz
39	0.0035	0.0889	0.00621	831.8	2728	0.11	0.0175	2250 kHz	0.36 lbs
40	0.0031	0.07874	0.00487	1049	3440	0.09	0.0137	2900 kHz	0.29 lbs

Voltage Drop Calculator by Gerald Newton http://www.electrician2.com
The following calculator calculates the voltage drop, and voltageat the end of the wire for American Wire Gauge from 4/0 AWG to 30 AWG, aluminumor copper wire. (Note: It just calculates the voltage drop, consult the abovetable for rules-of-thumb, or your local or national electrical code or yourelectrician to decide what is legal!) Note that the voltage drop does notdepend on the input voltage, just on the resistance of the wire and the load inamps.

This chart of American Wire Gauge (AWG) wire sizes and rated ampacities is data intended for the pleasure of our readers only. Typographical errors, etc. are probable, since the typist is not a professional (our CEO). Please point out errors. The data listed are incomplete and should be used as a guideline only. Please contact manufacturers for the latest data.

We hope that this information is helpful. Now go out and design something that needs a charger, power supply, or battery pack!

Wire Gauge and Current Limits Including Skin Depth
and Tensile Strength (2024)

FAQs

What is the maximum current for a wire gauge? ›

American Wire Gauge standards range from 0000 (which can handle up to 302 amps) to 40 (which can handle up to 0.0137 amps). Most household and commercial wiring demands range from 2 (95 amp maximum) or 3 (85 amp maximum) to 14 (15 amp maximum).

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What is 0.82 mm2 to AWG? ›

For example, 18 AWG conductor is approximately 0.82mm2.

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What gauge wire is needed for a 20 amp circuit? ›

A 20-amp circuit, protected by a 20-amp breaker or fuse, must be served by 12-gauge or 10-gauge wire. The easiest way to determine whether a circuit is 15 or 20 amps is to look at the corresponding breaker or fuse in the breaker panel.

Learn More ›

What is the wire gauge size in order? ›

American Wire Gauge Conversion Chart (AWG)

Gauge No.	Inches	Millimeters
1	0.289297	7.348
2	0.257626	6.544
3	0.229423	5.827
4	0.204307	5.189

64 more rows

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Do wires have a current limit? ›

Yes. Electricians have tables that show the ampacity, or the amount of current a particular wire can carry. The resistance of the wire is one limiting factor; temperature is another. It also depends on what the wire is made of.

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What is the maximum current capacity of wire? ›

Maximum Ampacity (Current Capacity) for Wire & Cable

12*	25A	30A
10*	35A	40A
8	50A	55A
6	65A	75A
4	85A	95A

10 more rows

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What gauge is .080 wire? ›

Wire Size Conversion Chart

Gauge	SWG (inch)	SWG (mm)
13	.092	2.34
14	.080	2.03
15	.072	1.83
16	.064	1.63

53 more rows

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How many amps can 12 AWG handle? ›

20 AMPS

Get More Info Here ›

What gauge is 0.5 MM2 wire? ›

Metric to AWG Conversion Table

Metric Size (mm2 cross-sectional area)	AWG Wire Gauge Size
0.5	20
0.75	19
1	18
1.5	16

24 more rows

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What happens if you use 14 gauge wire on a 20 amp circuit? ›

Note that a 14 gauge wire on a 20 amp circuit is not the correct size, as it is only rated to handle up to 15 Amp in residential applications. Using 14 AWG for a 20 Amp breaker will result in overheating and a risk of electrical fire. Using a 10 AWG wire for a 20 amp circuit is possible and safe but not cost-effective.

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Is it OK to replace a 15 amp breaker with a 20 amp? ›

Replacing a 15-amp breaker with a 20-amp breaker can be risky if not done correctly. Some potential risks include: Overloading the Wiring: A 15-amp breaker is typically connected to 14 AWG (American Wire Gauge) wire, which is not rated to handle the 20-amp current.

How far can you run 10/2 wire on a 20 amp breaker? ›

How far can I run 10/2 wire? You can run up to 50' of 10/2 wire before there is enough voltage loss to matter.

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What happens if a wire gauge is too big? ›

If you use an inappropriately sized wire, it may end up melting due to the high amounts of flowing current.

	Copper	Aluminum
12	20	20
10	30	30
8	40	40
6	55	50