sq mm to AWG Converter
Convert square millimeters to American Wire Gauge with precision matching, comprehensive specifications, and professional electrical engineering data
Formula: Convert area to diameter, then AWG = -39 × log₁₀(diameter) + 36
This calculator converts wire cross-sectional area in square millimeters to the equivalent American Wire Gauge (AWG) size.
Complete sq mm to AWG Conversion Reference
Detailed cross-sectional area to wire gauge conversion with electrical specifications, ampacity ratings, and professional applications
| Area (sq mm) | AWG Size | Diameter (mm) | Ampacity (A) | Resistance (Ω/km) | Typical Applications |
|---|---|---|---|---|---|
| 0.051 | 30 | 0.255 | 0.5 | 103.2 | Magnet wire, fine electronics, precision instruments |
| 0.081 | 28 | 0.321 | 0.8 | 64.9 | Thermocouple wire, instrumentation, sensor cables |
| 0.129 | 26 | 0.405 | 1 | 40.8 | Computer cables, telephone wire, data transmission |
| 0.205 | 24 | 0.511 | 1.5 | 25.7 | Signal cables, low power electronics, control circuits |
| 0.326 | 22 | 0.644 | 2.5 | 16.1 | Control circuits, alarm systems, communication |
| 0.518 | 20 | 0.812 | 4 | 10.2 | Lighting circuits, control panels, low voltage |
| 0.823 | 18 | 1.024 | 7 | 6.39 | Appliance cords, fixture wiring, extension cords |
| 1.31 | 16 | 1.291 | 10 | 4.02 | Extension cords, outlet circuits, small appliances |
| 2.08 | 14 | 1.628 | 15 | 2.53 | Branch circuits, outlets, lighting, general wiring |
| 3.31 | 12 | 2.053 | 20 | 1.59 | Kitchen circuits, bathroom outlets, air conditioning |
| 5.26 | 10 | 2.588 | 30 | 1 | Electric dryers, ranges, large appliances |
| 8.37 | 8 | 3.264 | 40 | 0.628 | Sub-panels, large appliances, electric water heaters |
| 13.3 | 6 | 4.115 | 55 | 0.395 | Service entrance, feeders, sub-panel connections |
| 21.2 | 4 | 5.189 | 70 | 0.248 | Service entrance, sub-panels, large load feeders |
| 26.7 | 3 | 5.827 | 85 | 0.197 | Service entrance, industrial feeders, large motors |
| 33.6 | 2 | 6.544 | 95 | 0.156 | Service entrance, large industrial loads, feeders |
| 42.4 | 1 | 7.348 | 110 | 0.124 | Service entrance, industrial applications, large feeders |
| 53.5 | 1/0 | 8.252 | 125 | 0.098 | Service entrance, industrial feeders, large installations |
| 67.4 | 2/0 | 9.266 | 145 | 0.078 | Service entrance, industrial applications, main feeders |
| 85 | 3/0 | 10.405 | 165 | 0.062 | Service entrance, industrial feeders, large facilities |
| 107.2 | 4/0 | 11.684 | 195 | 0.049 | Service entrance, industrial feeders, major installations |
Bridging Global Standards: IEC sq mm to AWG
Converting from a metric cross-sectional area (sq mm) to the AWG system is a common requirement for engineers integrating European or Asian components into North American systems. Here's what you need to know.
The "Closest Match" Challenge
IEC 60228 (for sq mm) and ASTM B258 (for AWG) define two different sets of standard sizes. A standard metric wire size like 2.5 sq mm does not have a direct, one-to-one equivalent in the AWG system. It falls between AWG 14 (2.08 sq mm) and AWG 12 (3.31 sq mm). Our calculator finds the nearest standard AWG size for you.
Rule of Thumb: Always Size Up
For safety and performance, the universal engineering best practice is to choose the next larger wire size. If your design calls for a 2.5 sq mm wire, you must select the next larger AWG size, which is AWG 12. Choosing the smaller AWG 14 would result in a wire with insufficient area, leading to overheating and excessive voltage drop.
Nominal Area vs. Physical Dimension
Remember that sq mm is a nominal cross-sectional area. For stranded wires, this is the sum of the areas of the individual strands. The physical diameter of a stranded wire will always be larger than a solid wire with the same sq mm area due to the air gaps. When selecting an AWG equivalent, you are matching the electrical properties (area), not necessarily the physical diameter.
Smart Matching
Algorithm: Euclidean distance minimization
Precision: 0.01 sq mm resolution
Variance: Percentage difference calculation
Classification: Automatic wire categorization
Optimization: Best fit selection
Area Analysis
Units: Square millimeters (mm²)
Range: 0.05 - 107.2 sq mm
Relationship: A = π × (d/2)²
Current: I = J × A
Power: P = I² × R × A
Selection Guide
Wire Cross-Section Categories
Professional categorization based on cross-sectional area and typical applications
Fine Wire
0.05 - 0.82 sq mm
AWG 30 - 18
Signal & control
Low voltage circuits
0.5 - 7A capacity
Standard Wire
1.3 - 8.4 sq mm
AWG 16 - 8
Branch circuits
General wiring
10 - 40A capacity
Heavy Wire
13.3 - 42.4 sq mm
AWG 6 - 1
Feeders & panels
Large appliances
55 - 110A capacity
Extra Heavy
53.5 - 107.2 sq mm
AWG 1/0 - 4/0
Service entrance
Industrial feeders
125 - 195A capacity
Cross-Sectional Area Engineering
Essential formulas and relationships for electrical engineering calculations
Current Calculations
Resistance & Power
Design Considerations
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