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Author: Michael Publish Time: 04-07-2025 Origin: Site
AWG to Metric conversion is instrumental for professionals, mainly engineers, installers, and procurement officers, who are operating in different areas with variant standards. The AWG (American Wire Gauge) is a method of measuring wires mainly in the US and Canada, while in the IEC 60228 system, which defines conductor size by area in square millimeters (mm²), most other regions use.
In this article, you will learn about the grounding of AWG, the comparison with the metric system, how the conversion is achieved, and how to pick the correct wire size according to your needs.
The AWG system was created in 1857 by Joseph Rogers Brown, a co-founder of Brown & Sharpe, to come up with a standardized sizing for wires that was desired during the industrial revolution. Before the fabrication of AWG, manufacturers used to have their own set of rules regarding wire size that created a lot of confusion and interoperability problems.
AWG system was created on the basis of the number of wire drawing processes that are required for a particular wire size. In this system:
AWG 26 wire will be subjected to drawing dies many times more than a 0000 (4/0) wire.
Greater the wire diameter number of AWG, lower the wire diameter.
This logarithmic scale brought conductor sizing to common ground and has eventually become the industry standard wire size in North America.
Solid round conductor is measured by diameter (insulation and jacket excluded)
Gauge number is used as measurement unit: for example, 10 AWG, 24 AWG
MCM (0000) and larger AWG are used for the measurements of wires with a larger diameter
Resistance, ampacity, and mechanical properties depend on the AWG size
Specifies wires in respect of cross-sectional area in mm²
The use of it is global for technical rules and requirement for electrical products
Is not based more on the geometrical sides, but on the resistivity of the conductor
CM: Area of the circle with 1 mil (1/1000 in) diameter.
MCM indicates quantity in thousands of circular mils (CM) and is a common nomenclature in the United States for electrical cables of large width.
MCM's equivalence is 1 mm² (1 MCM = 0.5067 mm²)
Here is a rule of thumb: 2 MCMs = 1 mm² with around 1.3% error.
Mostly found in industrial cables such as Belden data cables and UL758 Tri-Rated wires
AWG | Diameter (in) | Diameter (mm) | Cross-sectional Area (mm²) |
0000 (4/0) | 0.46 | 11.68 | 107.2 |
000 (3/0) | 0.41 | 10.4 | 85 |
00 (2/0) | 0.365 | 9.27 | 67.4 |
0 (1/0) | 0.325 | 8.25 | 53.5 |
1 | 0.289 | 7.35 | 42.4 |
2 | 0.258 | 6.54 | 33.6 |
4 | 0.204 | 5.19 | 21.1 |
6 | 0.162 | 4.11 | 13.3 |
8 | 0.129 | 3.26 | 8.36 |
10 | 0.102 | 2.59 | 5.26 |
12 | 0.081 | 2.05 | 3.31 |
14 | 0.064 | 1.63 | 2.08 |
16 | 0.051 | 1.29 | 1.31 |
18 | 0.04 | 1.02 | 0.82 |
20 | 0.032 | 0.81 | 0.52 |
22 | 0.025 | 0.65 | 0.33 |
24 | 0.02 | 0.51 | 0.2 |
26 | 0.016 | 0.4 | 0.13 |
Note: Metric cross-sectional areas are approximate and based on solid copper conductors.
For values not in the table:
AWG to Diameter (mm):
Diameter (mm) = 0.127 × 92(36 − AWG)/39
Cross-sectional Area (mm²):
Area (mm²) = π / 4 × diameter²
As the AWG number goes up, the wire gets thinner (thinner wire = higher resistance). Notice that in AC applications, they are prone to skin effect where current only flows along the surface of the conductor at higher frequencies. This law literally forms a relationship of resistance to frequency.
AWG with lower number (thicker) = less resistance and therefore, better for longer distances or higher thickness.
With higher AWG (thinner) = more resistance, good for short distances or low-powered devices
Factor | Impact |
Current (Amps) | Determines minimum wire cross-section |
Voltage Drop | Longer runs need larger wires |
Frequency | Affects skin effect and resistance |
Installation Type | Temperature ratings, bundling, conduit use |
Standards | UL, NEC, IEC, and local codes |
AWG | Approx. mm² | Typical Use |
24 | ~0.2 mm² | Data cable, Ethernet |
18 | ~0.8 mm² | LED lighting, control wiring |
14 | ~2.0 mm² | Residential wiring, lighting |
10 | ~5.3 mm² | Power circuits, automotive |
6 | ~13.3 mm² | Main feeders, HVAC |
2 | ~33.6 mm² | Industrial power |
However, the conversation about AWG and metric systems is not tame, and it is more about the understanding of cross systems. This helps in decision-making that is supported by evidence and regulation in electrical design and connection. The knowledge of using AWG charts, mm² cables, and the practices like MCM for large conductors in the connection is inevitable for the safety, functionality, and efficiency of such systems.
If you find that the guide does not center on your scenario, you might want to get in touch with your supplier or a technical expert. Many manufacturers like Belden or The Cable Lab could provide such personalized assistance or even an online calculator, which could help you to make a proper selection.
michael@zion-communication.com
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