Wire Size report

Whenever a circuit is extended or rewired, or when any new circuit is installed, it is critical that the new wiring is made with wire conductors that are correctly sized for the circuit's amperage rating. The higher the circuit's amperage rating, the larger the electrical wires need to be to avoid excess heat that can melt wires and cause fires.

The wire is sized by the American Wire Gauge (AWG) system. Wire gauge refers to the physical size of the wire, rated with a numerical designation that runs opposite to the diameter of the conductors. In other words, the smaller the wire gauge number, the larger the wire diameter. Standard sizes include 14-, 12-, 10-, 8-, 6-, and 2- gauge wire. The size of the wire dictates how much current can safely pass through the wire.

If you have shopped for electrical wire, you may have noticed that there are many types and sizes of wire to choose from. Different types of wire are intended for various uses, but knowing the correct wire size or gauge is key to making the right choice with any of these wire types. The following article explained the wire sizes and how to check the numbers.

Electrical Cable Parts

Whether a home or a commercial building, the wire and cable aisle is a very messy place. Before determining the size of the wires, you need to learn how to identify different cable types and their uses to ensure that you find the cables you need and the wiring safely.

Cable And Wire

People often use these terms interchangeably and are often confused by these two types, but there is a difference you should know:

• Cable is an assembly of two or more wires in a single jacket.
• Wires are the individual insulated or bare conductors inside the coat.

Wire Gauge

Wire gauge refers to the physical size of the wire. You can find the number on cables, the rated with a numerical designation that runs opposite to the diameter of the conductors. The smaller the wire gauge number, the larger the wire diameter. The most common sizes you'll find in residential work are 14-gauge and 12-gauge. Larger appliances such as electric stoves, water heaters, dryers, and central air units will often use 10-, 8- or even 6-gauge wire.

Electrical cable current is measured in ampacity, and each wire gauge has a maximum safe carrying capacity. For standard non-metallic (NM) cable, these amperage capacities are as follows:

Amperage Capacities for Standard Non-Metallic (NM) Cable
14-gauge wire	15 amps
12-gauge wire	20 amps
10-gauge wire	30 amps
8-gauge wire	40 amps
6-gauge wire	55 amps
4-gauge wire	70 amps
3-gauge wire	85 amps
2-gauge wire	95 amps

Cable by the Numbers

An electrical cable is classified by two numbers separated by a hyphen, such as 14-2. The first number denotes the wire's gauge, and the second represents the number of wires inside the electrical cable.

Wire Size Guide

It is vital to know the sizes in the cable to ensure it carries an appropriate amount of current securely. The gauge rank also determines the resistance of the wire and its weight per unit length. Each wire size has a maximum current limit that a wire can handle before damage occurs. It is essential to pick the correct size of wire so that the wire doesn't overheat. The following is a wire size chart that shows allowable ampacities in different situations.

AWG	Diameter(inch)	Diameter(mm)	Area(mm2)
0000	0.46	11.68	107.16
000	0.4096	10.40	84.97
00	0.3648	9.27	67.40
0	0.3249	8.25	53.46
1	0.2893	7.35	42.39
2	0.2576	6.54	33.61
3	0.2294	5.83	26.65
4	0.2043	5.19	21.14
5	0.1819	4.62	16.76
6	0.162	4.11	13.29
7	0.1443	3.67	10.55
8	0.1285	3.26	8.36
9	0.1144	2.91	6.64
10	0.1019	2.59	5.26
11	0.0907	2.30	4.17
12	0.0808	2.05	3.31
13	0.072	1.83	2.62
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	0.032	0.82	0.52
21	0.0285	0.72	0.41
22	0.0254	0.65	0.333
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
27	0.0142	0.36	0.10
28	0.0126	0.32	0.08
29	0.0113	0.29	0.06
30	0.01	0.254	0.05

Wire Size	60°C(140°F)	75°C(167°F)	90°C(194°F)	60°C(140°F)	75°C(167°F)	90°C(194°F)
AWGorkcmil	TW,UF	RHW,THW,THWN	TBS,SA,SIS	TW,UF	RHW,THW,THWN	TBS,SA,SIS
COPPER				ALUMINUM
14	20	20	25	-	-	-
12	25	25	30	20	20	25
10	30	35	40	25	30	35
8	40	50	55	30	40	45
6	55	65	75	40	50	60
4	70	85	95	55	65	75
3	85	100	110	65	75	85
2	95	115	130	75	90	100
1	110	130	150	85	100	115
1/0	125	150	170	100	120	135
2/0	145	175	195	115	135	150
3/0	165	200	225	130	155	175
4/0	195	230	260	150	180	205
250	215	255	290	170	205	230
300	240	285	320	190	230	255
350	260	310	350	210	250	280
400	280	335	380	225	270	305
500	320	380	430	260	310	350
600	355	420	475	285	340	385
700	385	460	520	310	375	420
750	400	475	535	320	385	435
800	410	490	555	330	395	450
900	435	520	585	355	425	480
1000	455	545	615	375	445	500
1250	495	590	665	405	485	545
1500	520	625	705	435	520	585
1750	545	650	735	455	545	615
2000	560	665	750	470	560	630

Different wires serve specific purposes. Knowing the correct wire size, also known as the gauge, will aid your electrical. The measurements determine the amount of current that can safely pass through the wire without generating damages. It is normal if you are confused about the wire size. We strongly recommend hiring a professional electrician to wire your home to ensure that all circuits are correct and safe.