The Comparative Guide to Wire Gauge and Wire Sizes

Wire gauge is an integral aspect of any electrical project, serving as the bridge between electrical capacity and physical size.

Understanding how wire gauge correlates with other size dimensions is critical for professionals and enthusiasts alike to ensure safety, compliance, and efficiency.

At The Crazy Wire Company, we delve into the intricate details of wire gauge, presenting a lucid explanation of its relationship to both millimetre and inch measurements, providing a foundation for informed decision-making in your wiring projects.

Providing this conversion is perhaps the most common request that we receive from our customer base. We hope that this simple article goes some way to answer the question.

Let’s go…

Deciphering Wire Gauge

Wire gauge, particularly the American Wire Gauge (AWG) system, is a standard unit of measure that denotes the diameter and cross-sectional area of a wire.

As in many other parts of the world, the metric system is widely used in the UK. It is therefore essential to understand how AWG corresponds to metric measurements. Our primary measurement for our wires is mm.

Conversion Between AWG and Metric Measurements

A wire’s gauge number is inversely related to its diameter: the smaller the gauge number, the larger the wire diameter.

Here’s a conversion table that outlines some common wire gauges and their equivalent sizes in both millimetres and inches:

AWG	Diameter (mm)	Diameter (inches)
0	11.684	0.46
0	10.404	0.4096
0	9.266	0.3648
0	8.252	0.3249
1	7.348	0.2893
2	6.544	0.2576
3	5.827	0.2294
4	5.189	0.2043
5	4.621	0.1819
6	4.115	0.162
7	3.665	0.1443
8	3.264	0.1285
9	2.906	0.1144
10	2.588	0.1019
11	2.305	0.0907
12	2.053	0.0808
13	1.828	0.072
14	1.628	0.0641
15	1.45	0.0571
16	1.291	0.0508
17	1.15	0.0453
18	1.024	0.0403
19	0.912	0.0359
20	0.812	0.032
21	0.723	0.0285
22	0.644	0.0253
23	0.573	0.0226
24	0.511	0.0201
25	0.455	0.0179
26	0.405	0.0159
27	0.361	0.0142
28	0.321	0.0126
29	0.286	0.0113
30	0.255	0.01
31	0.227	0.00893
32	0.202	0.00795
33	0.18	0.00708
34	0.16	0.0063
35	0.143	0.00561
36	0.127	0.005
37	0.113	0.00445
38	0.101	0.00397
39	0.089	0.00353
40	0.079	0.00314
41	0.071	0.0028
42	0.063	0.00249
43	0.056	0.00222
44	0.05	0.00197
45	0.044	0.00176
46	0.04	0.00157
47	0.036	0.0014
48	0.032	0.00124
49	0.029	0.00111
50	0.025	0.00099
51	0.023	0.00089
52	0.02	0.00079
53	0.018	0.00071
54	0.016	0.00063
55	0.014	0.00056
56	0.013	0.0005
57	0.012	0.00045
58	0.01	0.0004
59	0.009	0.00036
60	0.008	0.00032
61	0.007	0.00028
62	0.006	0.00025
63	0.005	0.00022
64	0.005	0.0002
65	0.004	0.00018
66	0.004	0.00016
67	0.003	0.00014
68	0.003	0.00013
69	0.003	0.00012
70	0.002	0.00011
71	0.002	0.0001
72	0.002	0.00009
73	0.002	0.00008
74	0.002	0.00007
75	0.001	0.00007
76	0.001	0.00006
77	0.001	0.00006
78	0.001	0.00005
79	0.001	0.00005
80	0.001	0.00004
81	0.001	0.00004
82	0.001	0.00004
83	0.001	0

This table acts as a handy reference, allowing you to effortlessly transition between systems, whether you’re sourcing materials internationally or working on projects that require familiarity with both imperial and metric systems.

Wire Gauge in Practice

When it comes to selecting wire, understanding gauge is crucial for several reasons:

Electrical Resistance: A lower-gauge (thicker) wire has less resistance and can carry more current, which is essential for reducing energy loss and heat buildup.
Current Capacity: Wire gauge directly affects how much current it can safely carry. Using a wire that’s too thin for the current load can lead to overheating and potential fire hazards.
Voltage Drop: Over long distances, a higher-gauge (thinner) wire will result in a significant voltage drop, which can affect the performance of electrical equipment.
Cost and Flexibility: Thicker wires are typically more expensive and less flexible, which might influence practical considerations for wiring in constrained spaces or budgets.

Wire Gauge and International Standards

Despite its prevalence, AWG is by no means universal. In order to ensure compliance and interoperability, different regions might use different gauge systems.

As mentioned earlier, the standard wire sizes in the UK, for example, are usually specified in millimetres.

Applications and Considerations

The application dictates the wire gauge. Household wiring typically uses 14 to 10 AWG wires for lighting and outlets, while automotive applications typically use 12 to 0 AWG wires, depending on the component. The wire gauge in electronics can be as high as 30 AWG or even smaller.

We supply wires all the way down to 44 AWG, which is very fine indeed.

Beyond Gauge - Other Important Wire Characteristics

Wire gauge isn’t the only consideration when choosing a wire.

The insulation type, temperature rating, and flexibility are just as crucial. Wires might also have additional coatings for corrosion resistance or colour-coded insulation for easy identification.

We specialise mainly in raw metal wires such as Stainless Steel and Nichrome.

What Is SWG Then?

Standard Wire Gauge (SWG) is a British system of wire sizes, traditionally used throughout the UK and in other countries which follow British standards. It was officially standardized by the British Board of Trade in 1884. The SWG system measures the diameter of conductive wires ranging from heavy, industrial cables to thin, delicate wires used in jewellery making.

SWG sizes are denoted by numbers that range from 7/0 (the largest size) to 50 (the smallest size). Unlike a straightforward numerical sequence, the SWG system’s wire diameter decreases as the gauge number increases. The thickness increments between the gauges in the SWG system are not uniform, and they generally get closer together as the wires get thinner.

Choosing the correct wire gauge is paramount for any electrical project, influencing safety, efficiency, and performance.

With The Crazy Wire Company’s expert guidance, you’re equipped to make the right choices, understanding the subtleties of wire gauge as it relates to different sizing systems. Remember, when in doubt, consult with a professional to ensure your electrical projects meet the necessary standards and are executed safely.

We intend to create 2 or more articles per week to discuss all aspects of our product range. Eventually, we hope to have guides that pretty much answer all questions in huge detail.

For more information on wire gauges and to view our extensive range of wire products, visit our site or contact our expert team for tailored advice on your specific wiring needs.

We offer also a massive range of stainless steel wire and nichrome wire through our store. Choose the wire that you want to work with and we’ll get spooling.

If you’re interesting in learning more about wire, check out our other blog on Everything You Need to Know About Wires.

We are also proud to supply this product on our highly popular eBay store, check us out there too.

Thank you for checking out our site.

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