Getting to know the size of your cable or steel goes a long way in ensuring that you purchase the right items for use. The standard measurement for wire and steel is in gauge. Most people rarely understand that unit, thus the conversion to mm.
The measurement varies from one item to another. The standard used for wires is different from steel. The thickness varies from one metal to another, making it confusing.
Steel and aluminum standards vary in thickness. Whether you’re trying to convert thicknesses for one thing or something like SAE, it’s always convenient to have a chart available!
Summary
The easiest way to convert wire & steel gauges to mm & inches is with the help of our charts below.
Here is a summary of the chart.
- 00 wire gauge has a thickness of 8.252mm.
- 2 wire gauge has a thickness of 6.543mm.
- 4 wire gauge has a thickness of 5.189mm.
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While dealing with wires and cables, knowing the difference between the two is good. A wire is an electrical conductor, while a cable is a group of conductors enclosed in a cover.
Wire gauge to mm chart
With a conversion chart, you can easily move from one unit of measurement to another without much struggle. The units are represented in inches & millimeters in the chart below.
Wire Number (Gauge) | A.W.G. Metric (MM) | A.W.G. or B&S (Inches) |
0000000 (7/0) | ………… | ………… |
000000 (6/0) | ………… | 0.58″ |
00000 (5/0) | ………… | 0.5165″ |
0000 (4/0) | 11.684mm | 0.46″ |
000 (3/0) | 10.404mm | 0.409642″ |
00 (2/0) | 9.266mm | 0.364796″ |
0 (1/0) | 8.252mm | 0.324861″ |
1 | 7.348mm | 0.289297″ |
2 | 6.543mm | 0.257627″ |
3 | 5.827mm | 0.229423″ |
4 | 5.189mm | 0.2043″ |
5 | 4.621mm | 0.1819″ |
6 | 4.115mm | 0.162″ |
7 | 3.665mm | 0.1443″ |
8 | 3.264mm | 0.1285″ |
9 | 2.906mm | 0.1144″ |
10 | 2.588mm | 0.1019″ |
11 | 2.304mm | 0.0907″ |
12 | 2.052mm | 0.0808″ |
13 | 1.829mm | 0.072″ |
14 | 1.628mm | 0.0641″ |
15 | 1.45mm | 0.0571″ |
16 | 1.291mm | 0.0508″ |
17 | 1.15mm | 0.0453″ |
18 | 1.024mm | 0.0403″ |
19 | 0.9119mm | 0.0359″ |
20 | 0.8128mm | 0.032″ |
21 | 0.7239mm | 0.0285″ |
22 | 0.6426mm | 0.0253″ |
23 | 0.574mm | 0.0226″ |
24 | 0.5106mm | 0.0201″ |
25 | 0.4547mm | 0.0179″ |
26 | 0.4038mm | 0.0159″ |
27 | 0.3606mm | 0.0142″ |
28 | 0.32mm | 0.0126″ |
29 | 0.287mm | 0.0113″ |
30 | 0.254mm | 0.01″ |
31 | 0.2261mm | 0.0089″ |
32 | 0.2032mm | 0.008″ |
33 | 0.1803mm | 0.0071″ |
34 | 0.1601mm | 0.0063″ |
35 | 0.1422mm | 0.0056″ |
36 | 0.127mm | 0.005″ |
37 | 0.1143mm | 0.0045″ |
38 | 0.1016mm | 0.004″ |
39 | 0.0889mm | 0.0035″ |
40 | 0.0787mm | 0.0031″ |
41 | 0.0711mm | 0.0028″ |
42 | 0.0635mm | 0.0025″ |
43 | 0.0559mm | 0.0022″ |
44 | 0.0508mm | 0.002″ |
45 | 0.0457mm | 0.0018″ |
46 | 0.0406mm | 0.0016″ |
47 | 0.035mm | 0.0014″ |
48 | 0.0305mm | 0.0012″ |
49 | 0.0279mm | 0.0011″ |
50 | 0.0254mm | 0.001″ |
51 | 0.0224mm | 0.00088″ |
52 | 0.0198mm | 0.00078″ |
53 | 0.0178mm | 0.0007″ |
54 | 0.0158mm | 0.00062″ |
55 | 0.014mm | 0.00055″ |
56 | 0.0124mm | 0.00049″ |
Steel gauge
The image below shows a steel gauge conversion chart. It includes the corresponding measurements for other metals of the corresponding gauge.
Gauge Number | Stainless Steel (mm) | Aluminum, Brass, Copper (mm) | Standard Steel (mm) | Galvanized Steel (mm) |
3 | 5.827 | 6.073 | ||
4 | 5.954 | 5.189 | 5.095 | |
5 | 5.555 | 4.62 | 5.314 | |
6 | 5.159 | 4.115 | 4.935 | |
7 | 4.763 | 3.665 | 4.554 | |
8 | 4.191 | 3.264 | 4.176 | |
9 | 3.967 | 2.906 | 3.797 | 3.891 |
10 | 3.571 | 2.588 | 3.416 | 3.51 |
11 | 3.175 | 2.304 | 3.038 | 3.132 |
12 | 2.779 | 2.052 | 2.657 | 2.753 |
13 | 2.38 | 1.829 | 2.278 | 2.372 |
14 | 1.984 | 1.628 | 1.897 | 1.994 |
15 | 1.786 | 1.45 | 1.709 | 1.803 |
16 | 1.588 | 1.29 | 1.519 | 1.613 |
17 | 1.427 | 1.151 | 1.367 | 1.461 |
18 | 1.27 | 1.024 | 1.214 | 1.311 |
19 | 1.11 | 0.912 | 1.062 | 1.158 |
20 | 0.953 | 0.813 | 0.912 | 1.006 |
21 | 0.874 | 0.724 | 0.836 | 0.93 |
22 | 0.792 | 0.643 | 0.759 | 0.853 |
23 | 0.714 | 0.574 | 0.683 | 0.777 |
24 | 0.635 | 0.536 | 0.607 | 0.701 |
25 | 0.556 | 0.455 | 0.531 | 0.627 |
26 | 0.475 | 0.404 | 0.455 | 0.551 |
27 | 0.437 | 0.361 | 0.417 | 0.513 |
28 | 0.396 | 0.32 | 0.378 | 0.475 |
29 | 0.358 | 0.287 | 0.343 | 0.437 |
30 | 0.318 | 0.254 | 0.305 | 0.399 |
31 | 0.277 | 0.226 | 0.267 | 0.361 |
32 | 0.259 | 0.203 | 0.246 | 0.34 |
33 | 0.239 | 0.18 | 0.229 | |
34 | 0.218 | 0.16 | 0.208 | |
35 | 0.198 | 0.142 | 0.191 | |
36 | 0.178 | 0.127 | 0.17 | |
37 | 0.168 | 0.113 | 0.163 | |
38 | 0.157 | 0.101 | 0.17 |
Sheet Metal Steel
Gauge Number | Stainless Steel (in) | Aluminum, Brass, Copper (in) | Standard Steel (in) | Galvanized Steel (in) |
3 | 0.2294 | 0.2391 | ||
4 | 0.2344 | 0.2043 | 0.2242 | |
5 | 0.2187 | 0.1819 | 0.2092 | |
6 | 0.2031 | 0.162 | 0.1943 | |
7 | 0.1875 | 0.1443 | 0.1793 | |
8 | 0.165 | 0.1285 | 0.1644 | |
9 | 0.1562 | 0.1144 | 0.1495 | 0.1532 |
10 | 0.1406 | 0.1019 | 0.1345 | 0.1382 |
11 | 0.125 | 0.0907 | 0.1196 | 0.1233 |
12 | 0.1094 | 0.0808 | 0.1046 | 0.1084 |
13 | 0.0937 | 0.072 | 0.0897 | 0.0934 |
14 | 0.0781 | 0.0641 | 0.0747 | 0.0785 |
15 | 0.0703 | 0.0571 | 0.0673 | 0.071 |
16 | 0.0625 | 0.0508 | 0.0598 | 0.0635 |
17 | 0.0562 | 0.0453 | 0.0538 | 0.0575 |
18 | 0.05 | 0.0403 | 0.0478 | 0.0516 |
19 | 0.0437 | 0.0359 | 0.0418 | 0.0456 |
20 | 0.0375 | 0.032 | 0.0359 | 0.0396 |
21 | 0.0344 | 0.0285 | 0.0329 | 0.0366 |
22 | 0.0312 | 0.0253 | 0.0299 | 0.0336 |
23 | 0.0281 | 0.0226 | 0.0269 | 0.0306 |
24 | 0.025 | 0.0211 | 0.0239 | 0.0276 |
25 | 0.0219 | 0.0179 | 0.0209 | 0.0247 |
26 | 0.0187 | 0.0159 | 0.0179 | 0.0217 |
27 | 0.0172 | 0.0142 | 0.0164 | 0.0202 |
28 | 0.0156 | 0.0126 | 0.0149 | 0.0187 |
29 | 0.0141 | 0.0113 | 0.0135 | 0.0172 |
30 | 0.0125 | 0.01 | 0.012 | 0.0157 |
31 | 0.0109 | 0.0089 | 0.0105 | 0.0142 |
32 | 0.0102 | 0.008 | 0.0097 | 0.0134 |
33 | 0.0094 | 0.0071 | 0.009 | |
34 | 0.0086 | 0.0063 | 0.0082 | |
35 | 0.0078 | 0.0056 | 0.0075 | |
36 | 0.007 | 0.005 | 0.0067 | |
37 | 0.0066 | 0.00445 | 0.0064 | |
38 | 0.0062 | 0.00396 | 0.0067 |
Do you want to buy more wires but don’t know where to start to make the best choice?
Fortunately for you, we can come to your aid.
We will give you all the steps you need to follow in choosing the best type of electric cable to suit your needs.

Electrical Safety Tips
When dealing with electricity, there is a need to observe safety tips. They ensure you minimize your danger of getting hurt when you are using it. The tips include:
a.) When working on electric cables, ensure that you have switched off the mains.
b.) Use the right cable for electric conduction to avoid damage to your property.
c.) Use the appropriate colors to represent the cables and their functions while in use.
d.) Install outlet covers to protect your kids from electrocution when not in use.
e.) Have multiple outlets to reduce the chances of overloading one.
Steel
Steel gauge is used in characterizing metal thickness in flat sheets. For instance, the metal is a foil when very thin. Thicker metals are known as plates. Just like in AWG, the system is based on non-linear measurements and represented in fractions of inches.
The steel gauge is not easy to read and convert to standard units of measurement. It requires a chart for easier conversion. The corresponding numbers range from 3 to 30 and are based on the weight of the metal sheet.
Here are some benefits of using steel for electrical wires.
- They are environmentally friendly and can be recycled.
- Steel wires are easy to install and maintain.
- They are fire-resistant
- They provide better insulation than other materials.
Based on the weight of the metal sheet, two different metals may vary in gauge despite having a similar thickness. To understand it properly and to make sure you get the right product, you need a conversion chart. It will help you change it to millimeters or inches.
How it started
It shares the same origin with the British system, based on the number of times it was drawn. They share similar characteristics, such as representation in fractions of inches. It has survived several generations, remaining the main method used until today.
How to read the chart
Reading a steel chart requires little time to understand the metal thickness it stands for. When one should consider the following feature:
- The distances between one gauge and another are not equidistant.
- The readings vary with the type of metal in use. Always consider the decimals to get accurate readings of the metal.
Conversion of mm to inches
Changing from millimeters to inches is as easy as using your phone calculator. Some phones also have an inbuilt inverter that converts several measurement units to another.
The conversion multiplier is 0.023937007874. Once you multiply your value in millimeters by this, you get your answer in inches.
There are also online converters that you can use to find the value in inches and vice versa.
Wire
Wire gauge shows the diameter from which you can easily get its current carrying capacity. You can easily get to know the physical appearance of a wire. It’ll provide you with information on the electrical resistance and the weight of the size.
With the standards being used, it is easier to determine the cable to use for a specific purpose. Using a cable to transmit more electricity than the recommended amount can damage the part. At times it can lead to your house burning if installed at home.
