AWG to mm2 Converter and Wire Gauge Reference
Convert AWG to mm2 and metric wire sizes with diameter, resistance, and ampacity data, then verify voltage drop and harness packaging.
What is AWG (American Wire Gauge)?
AWG is the standardized wire gauge system used in North America. Lower numbers mean thicker wire — AWG 0000 (107.2 mm²) is the thickest, AWG 36 (0.013 mm²) is the thinnest. Each 3-gauge decrease doubles the cross-sectional area, and each 10-gauge decrease multiplies area by roughly 10.
Reference: ASTM B258, IEC 60228
How Engineers Use AWG Conversions in Real Harness Work
A conversion table is only the first step. After you translate AWG to metric, you still need to verify voltage drop, packaging, and documentation so the chosen wire size survives the real application instead of just matching a catalog number.
Check Voltage Drop
Confirm that the converted size still meets the circuit length, current, and allowable drop.
Check Bundle OD
A larger equivalent metric size can change conduit fill, backshell size, and bundle routing.
Document the Workflow
Capture the final wire choice in a schematic-to-manufacturing flow instead of a disconnected spreadsheet note.
Quick Converter
Get wire sizing tips & updates:
By subscribing, you agree to receive updates from Signetronics LLC.
AWG Reference Table
| AWG | mm² | Ø mm | Ø in | Ω/km | Amps |
|---|---|---|---|---|---|
| 0000 | 107.2 | 11.684 | 0.46 | 0.1608 | 302 |
| 000 | 85 | 10.405 | 0.4096 | 0.2028 | 239 |
| 00 | 67.4 | 9.266 | 0.3648 | 0.2557 | 190 |
| 0 | 53.5 | 8.251 | 0.3249 | 0.3224 | 150 |
| 1 | 42.4 | 7.348 | 0.2893 | 0.4066 | 119 |
| 2 | 33.6 | 6.544 | 0.2576 | 0.5127 | 94 |
| 3 | 26.7 | 5.827 | 0.2294 | 0.6465 | 75 |
| 4 | 21.2 | 5.189 | 0.2043 | 0.8152 | 60 |
| 5 | 16.8 | 4.621 | 0.1819 | 1.028 | 47 |
| 6 | 13.3 | 4.115 | 0.162 | 1.296 | 37 |
| 7 | 10.5 | 3.665 | 0.1443 | 1.634 | 30 |
| 8 | 8.37 | 3.264 | 0.1285 | 2.061 | 24 |
| 9 | 6.63 | 2.906 | 0.1144 | 2.599 | 19 |
| 10 | 5.26 | 2.588 | 0.1019 | 3.277 | 15 |
| 11 | 4.17 | 2.305 | 0.0907 | 4.132 | 12 |
| 12 | 3.31 | 2.053 | 0.0808 | 5.211 | 9.3 |
| 13 | 2.62 | 1.828 | 0.072 | 6.571 | 7.4 |
| 14 | 2.08 | 1.628 | 0.0641 | 8.286 | 5.9 |
| 15 | 1.65 | 1.45 | 0.0571 | 10.45 | 4.7 |
| 16 | 1.31 | 1.291 | 0.0508 | 13.17 | 3.7 |
| 17 | 1.04 | 1.15 | 0.0453 | 16.61 | 2.9 |
| 18 | 0.823 | 1.024 | 0.0403 | 20.95 | 2.3 |
| 19 | 0.653 | 0.912 | 0.0359 | 26.42 | 1.8 |
| 20 | 0.518 | 0.812 | 0.032 | 33.31 | 1.5 |
| 21 | 0.41 | 0.723 | 0.0285 | 42 | 1.2 |
| 22 | 0.326 | 0.644 | 0.0254 | 52.96 | 0.92 |
| 23 | 0.258 | 0.573 | 0.0226 | 66.79 | 0.73 |
| 24 | 0.205 | 0.511 | 0.0201 | 84.22 | 0.58 |
| 25 | 0.162 | 0.455 | 0.0179 | 106.2 | 0.46 |
| 26 | 0.129 | 0.405 | 0.0159 | 133.9 | 0.36 |
| 27 | 0.102 | 0.361 | 0.0142 | 168.9 | 0.29 |
| 28 | 0.081 | 0.321 | 0.0126 | 212.9 | 0.23 |
| 29 | 0.064 | 0.286 | 0.0113 | 268.5 | 0.18 |
| 30 | 0.051 | 0.255 | 0.01 | 338.6 | 0.14 |
| 31 | 0.04 | 0.227 | 0.0089 | 426.9 | 0.11 |
| 32 | 0.032 | 0.202 | 0.008 | 538.3 | 0.09 |
| 33 | 0.025 | 0.18 | 0.0071 | 678.8 | 0.07 |
| 34 | 0.02 | 0.16 | 0.0063 | 856 | 0.06 |
| 35 | 0.016 | 0.143 | 0.0056 | 1079 | 0.05 |
| 36 | 0.013 | 0.127 | 0.005 | 1361 | 0.04 |
* Max amps based on single conductor in free air at 30°C ambient. Derate for bundling and higher temperatures.
Converted the size?
The next engineering step is checking voltage drop and packaging, not stopping at the conversion table.
Converted the size? Check voltage drop next →Next Steps
Related Terms
About AWG Wire Sizes
American Wire Gauge (AWG) is the standard system for measuring wire diameter in North America. Confusingly, smaller AWG numbers mean larger wires. For example, AWG 4 is much thicker than AWG 24.
AWG vs Metric (mm²)
Most of the world uses metric wire sizes based on cross-sectional area in mm². The ISO 6722 standard defines common automotive wire sizes like 0.5, 1.0, 1.5, 2.5, and 4.0 mm². The conversions below show the closest standard metric sizes, not exact equivalents:
Common Conversions
- AWG 18 ≈ 0.75 mm² (common for signal wires)
- AWG 16 ≈ 1.5 mm² (light-duty power)
- AWG 14 ≈ 2.5 mm² (standard power)
- AWG 12 ≈ 4.0 mm² (high-current circuits)
- AWG 10 ≈ 6.0 mm² (heavy-duty power)
AWG to Inches Conversion
The AWG system is based on wire diameter measured in mils (thousandths of an inch). AWG 36, the smallest standard gauge, has a diameter of exactly 5 mils (0.005 inches). Each step down in AWG number increases the diameter by a ratio of approximately 1.123 (more precisely, 92^(1/39) ≈ 1.12293).
| AWG | Diameter (inches) | Diameter (mils) | Diameter (mm) |
|---|---|---|---|
| 10 | 0.1019" | 101.9 | 2.588 |
| 12 | 0.0808" | 80.8 | 2.053 |
| 14 | 0.0641" | 64.1 | 1.628 |
| 16 | 0.0508" | 50.8 | 1.291 |
| 18 | 0.0403" | 40.3 | 1.024 |
| 20 | 0.0320" | 32.0 | 0.812 |
| 22 | 0.0254" | 25.4 | 0.644 |
To convert AWG to inches: diameter (in) = 0.005 × 92((36 - AWG) / 39). For quick reference, AWG 22 is almost exactly 1/40 inch (0.025"), and AWG 10 is about 1/10 inch (0.102").
NEC Ampacity Reference (Table 310.16)
Allowable ampacities for insulated copper conductors. Values are for not more than 3 current-carrying conductors in raceway, cable, or earth at 30°C ambient.
| AWG | mm² | 60°C (TW, UF) | 75°C (THW, THWN) | 90°C (THHN, XHHW) |
|---|---|---|---|---|
| 14 | 2.08 | 15 A | 20 A | 25 A |
| 12 | 3.31 | 20 A | 25 A | 30 A |
| 10 | 5.26 | 30 A | 35 A | 40 A |
| 8 | 8.37 | 40 A | 50 A | 55 A |
| 6 | 13.3 | 55 A | 65 A | 75 A |
| 4 | 21.2 | 70 A | 85 A | 95 A |
| 2 | 33.6 | 95 A | 115 A | 130 A |
| 1/0 | 53.5 | 125 A | 150 A | 170 A |
Source: NEC 2020, Table 310.16. Apply correction factors for ambient temperatures above 30°C and more than 3 conductors in raceway.
AWG to ISO 6722 (Automotive Metric) Comparison
ISO 6722 defines standard metric wire sizes used in automotive applications worldwide. Here are the closest equivalents:
| AWG | Exact mm² | ISO 6722 Size | Typical Application |
|---|---|---|---|
| 20 | 0.52 | 0.5 mm² | Low-current signals, sensors |
| 18 | 0.82 | 0.75 mm² | Interior lights, switches |
| 16 | 1.31 | 1.0 mm² / 1.5 mm² | Exterior lights, relays |
| 14 | 2.08 | 2.5 mm² | Fuel pump, blower motor |
| 12 | 3.31 | 4.0 mm² | Headlights, cooling fan |
| 10 | 5.26 | 6.0 mm² | Alternator, starter solenoid |
| 8 | 8.37 | 10 mm² | High-current distribution |
Note: AWG and ISO sizes do not match exactly. When substituting, always size up to the next larger metric size if the exact AWG equivalent falls between standard ISO sizes.
Why Use AWG vs Metric?
AWG (American Wire Gauge) is logarithmic. Every 6 steps doubles the wire diameter, and every 3 steps doubles the cross-sectional area. This system is dominant in the US, especially for MIL-SPEC and aerospace wiring (e.g., AS22759).
Metric (mm²) is linear and directly represents the cross-sectional area of the conductor. This makes calculating voltage drop and current density much more intuitive (Resistance ∝ 1/Area). Almost all automotive wiring (ISO 6722) uses metric sizing.