12 AWG is 2.053mm across, the wire size the US electrical code requires for 20-amp kitchen and bathroom outlets. 14 AWG (1.628mm) is one size down, rated for 15 amps and standard for lighting circuits.
American Wire Gauge (AWG) isn't a metric or imperial length. It's a standardised numbering where each step changes the wire's cross-sectional area by a fixed ratio. That makes it computable exactly: diameter (mm) = 0.127 × 92^((36 − AWG) / 39). Every value below comes directly from that formula, not a rounded lookup.
| AWG | Diameter (mm) | Diameter (in) | Area (mm²) |
|---|---|---|---|
| 0000 (4/0) | 11.684 mm | 0.4600" | 107.22 mm² |
| 000 (3/0) | 10.405 mm | 0.4096" | 85.03 mm² |
| 00 (2/0) | 9.266 mm | 0.3648" | 67.43 mm² |
| 0 | 8.251 mm | 0.3249" | 53.48 mm² |
| 1 | 7.348 mm | 0.2893" | 42.41 mm² |
| 2 | 6.544 mm | 0.2576" | 33.63 mm² |
| 4 | 5.189 mm | 0.2043" | 21.15 mm² |
| 6 | 4.115 mm | 0.1620" | 13.30 mm² |
| 8 | 3.264 mm | 0.1285" | 8.37 mm² |
| 10 | 2.588 mm | 0.1019" | 5.26 mm² |
| 12 | 2.053 mm | 0.0808" | 3.31 mm² |
| 14 | 1.628 mm | 0.0641" | 2.08 mm² |
| 16 | 1.291 mm | 0.0508" | 1.31 mm² |
| 18 | 1.024 mm | 0.0403" | 0.82 mm² |
| 20 | 0.8118 mm | 0.0320" | 0.5176 mm² |
| 22 | 0.6438 mm | 0.0253" | 0.3255 mm² |
| 24 | 0.5106 mm | 0.0201" | 0.2047 mm² |
| 26 | 0.4049 mm | 0.0159" | 0.1288 mm² |
| 28 | 0.3211 mm | 0.0126" | 0.0810 mm² |
| 30 | 0.2546 mm | 0.0100" | 0.0509 mm² |
| 32 | 0.2019 mm | 0.0080" | 0.0320 mm² |
| 34 | 0.1601 mm | 0.0063" | 0.0201 mm² |
| 36 | 0.1270 mm | 0.0050" | 0.0127 mm² |
| 38 | 0.1007 mm | 0.0040" | 0.0080 mm² |
| 40 | 0.0799 mm | 0.0031" | 0.0050 mm² |