Wire Gauge (AWG) Sizes
All 44 American Wire Gauge sizes from 4/0 through 40. AWG is geometric — each step down multiplies the diameter by 921/39 (≈ 12.3%), so the diameter alone identifies a gauge. Looking for sheet metal instead? Sheet uses a different gauge scale — see the sheet-metal gauge chart.
Identify a wire from its diameter
Decimal inches by default; add “mm” for millimeters. Try:
How to measure
Strip the insulation and caliper the bare conductor — jacket thickness varies by insulation type and swamps the ~12% step between gauges. Stranded wire bundles measure oversize: the gauge names the equivalent solid cross-section, so identify stranded wire from the marking when possible.
AWG chart
| AWG | Diameter | mm | Area | mm² |
|---|---|---|---|---|
| 4/0 | 0.4600″ | 11.684 | 211.6 kcmil | 107.22 |
| 3/0 | 0.4096″ | 10.404 | 167.8 kcmil | 85.01 |
| 2/0 | 0.3648″ | 9.266 | 133.1 kcmil | 67.43 |
| 1/0 | 0.3249″ | 8.252 | 105.6 kcmil | 53.49 |
| 1 | 0.2893″ | 7.348 | 83,694 cmil | 42.41 |
| 2 | 0.2576″ | 6.543 | 66,358 cmil | 33.62 |
| 3 | 0.2294″ | 5.827 | 52,624 cmil | 26.67 |
| 4 | 0.2043″ | 5.189 | 41,738 cmil | 21.15 |
| 5 | 0.1819″ | 4.620 | 33,088 cmil | 16.77 |
| 6 | 0.1620″ | 4.115 | 26,244 cmil | 13.30 |
| 7 | 0.1443″ | 3.665 | 20,822 cmil | 10.55 |
| 8 | 0.1285″ | 3.264 | 16,512 cmil | 8.37 |
| 9 | 0.1144″ | 2.906 | 13,087 cmil | 6.63 |
| 10 | 0.1019″ | 2.588 | 10,384 cmil | 5.26 |
| 11 | 0.0907″ | 2.304 | 8,226 cmil | 4.17 |
| 12 | 0.0808″ | 2.052 | 6,529 cmil | 3.31 |
| 13 | 0.0720″ | 1.829 | 5,184 cmil | 2.63 |
| 14 | 0.0641″ | 1.628 | 4,109 cmil | 2.08 |
| 15 | 0.0571″ | 1.450 | 3,260 cmil | 1.65 |
| 16 | 0.0508″ | 1.290 | 2,581 cmil | 1.31 |
| 17 | 0.0453″ | 1.151 | 2,052 cmil | 1.04 |
| 18 | 0.0403″ | 1.024 | 1,624 cmil | 0.8229 |
| 19 | 0.0359″ | 0.912 | 1,289 cmil | 0.6530 |
| 20 | 0.0320″ | 0.813 | 1,024 cmil | 0.5189 |
| 21 | 0.0285″ | 0.724 | 812 cmil | 0.4116 |
| 22 | 0.0253″ | 0.643 | 640 cmil | 0.3243 |
| 23 | 0.0226″ | 0.574 | 511 cmil | 0.2588 |
| 24 | 0.0201″ | 0.511 | 404 cmil | 0.2047 |
| 25 | 0.0179″ | 0.455 | 320 cmil | 0.1624 |
| 26 | 0.0159″ | 0.404 | 253 cmil | 0.1281 |
| 27 | 0.0142″ | 0.361 | 202 cmil | 0.1022 |
| 28 | 0.0126″ | 0.320 | 159 cmil | 0.0804 |
| 29 | 0.0113″ | 0.287 | 128 cmil | 0.0647 |
| 30 | 0.0100″ | 0.254 | 100 cmil | 0.0507 |
| 31 | 0.0089″ | 0.226 | 79 cmil | 0.0401 |
| 32 | 0.0080″ | 0.203 | 64 cmil | 0.0324 |
| 33 | 0.0071″ | 0.180 | 50 cmil | 0.0255 |
| 34 | 0.0063″ | 0.160 | 40 cmil | 0.0201 |
| 35 | 0.0056″ | 0.142 | 31 cmil | 0.0159 |
| 36 | 0.0050″ | 0.127 | 25 cmil | 0.0127 |
| 37 | 0.0045″ | 0.114 | 20 cmil | 0.0103 |
| 38 | 0.0040″ | 0.102 | 16 cmil | 0.0081 |
| 39 | 0.0035″ | 0.089 | 12 cmil | 0.0062 |
| 40 | 0.0031″ | 0.079 | 10 cmil | 0.0049 |
Areas are derived from the nominal diameter (cmil = mils²; mm² = π/4 × d²). Ampacity and resistance are deliberately not listed: current ratings depend on insulation temperature rating, bundling, and the electrical code in force — properties of the installation, not the gauge. Consult the applicable code tables.