Standard metric wire sizes used internationally. Defined by IEC 60228, these sizes are specified in mm² (square millimeters) cross-sectional area. Used in Europe, Asia, Australia, and most countries outside North America.
| Size (mm²) | Diameter (mm) | ≈ AWG | Amps (Cu) | Amps (Al) | Max Ω/km (Cu) | kg/km (Cu) |
|---|---|---|---|---|---|---|
| 0.5 mm² | 0.798 | 20 | 3 | — | 36 | 4.48 |
| 0.75 mm² | 0.977 | 18 | 6 | — | 24.5 | 6.72 |
| 1.0 mm² | 1.128 | 17 | 10 | — | 18.1 | 8.96 |
| 1.5 mm² | 1.382 | 15 | 14.5 | — | 12.1 | 13.44 |
| 2.5 mm² | 1.784 | 13 | 19.5 | 16 | 7.41 | 22.4 |
| 4 mm² | 2.257 | 11 | 26 | 21 | 4.61 | 35.84 |
| 6 mm² | 2.764 | 9 | 34 | 27 | 3.08 | 53.76 |
| 10 mm² | 3.568 | 7 | 46 | 36 | 1.83 | 89.6 |
| 16 mm² | 4.514 | 5 | 61 | 49 | 1.15 | 143.36 |
| 25 mm² | 5.642 | 3 | 80 | 63 | 0.727 | 224.0 |
| 35 mm² | 6.676 | 2 | 99 | 77 | 0.524 | 313.6 |
| 50 mm² | 7.979 | 1/0 | 119 | 93 | 0.387 | 448.0 |
| 70 mm² | 9.441 | 2/0 | 151 | 118 | 0.268 | 627.2 |
| 95 mm² | 10.998 | 3/0 | 182 | 142 | 0.193 | 851.2 |
| 120 mm² | 12.361 | 250 kcmil | 210 | 164 | 0.153 | 1075.2 |
| 150 mm² | 13.82 | 300 kcmil | 240 | 189 | 0.124 | 1344.0 |
| 185 mm² | 15.348 | 350 kcmil | 273 | 215 | 0.0991 | 1657.6 |
| 240 mm² | 17.481 | 500 kcmil | 321 | 252 | 0.0754 | 2150.4 |
| 300 mm² | 19.544 | 600 kcmil | 367 | 289 | 0.0601 | 2688.0 |
Copper ampacity: IEC 60364-5-52 method A1 (PVC insulation, conduit in an insulated wall, two loaded conductors, 30°C); 0.5–1.0 mm² are BS 7671 flexible-cord ratings. Resistance: IEC 60228 class 2 maximum at 20°C. Above 95 mm² the closest North American sizes are kcmil, not AWG.
12 AWG (3.31 mm²) is closest to the IEC standard 2.5 mm² size, though 2.5 mm² is slightly smaller. The next metric size up is 4 mm², which exceeds 12 AWG. For an exact match, use the AWG to mm² conversion table.
2.5 mm² wire (roughly equivalent to 13 AWG) is the standard size for 20A outlet circuits in European and international wiring. It has an ampacity of approximately 20A and is used for kitchen, bathroom, and general-purpose circuits under IEC standards.
IEC 60228 specifies wire sizes in mm² (cross-sectional area), while AWG uses an arbitrary gauge number where higher numbers mean smaller wire. IEC sizes are intuitive: larger mm² = larger wire. Standard IEC sizes: 0.5, 0.75, 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 240, 300 mm².