AWG Wire Gauge Chart
Complete American Wire Gauge reference — diameter, area, resistance, and NEC ampacity ratings for copper conductors from 4/0 to 30 AWG.
| AWG | Dia (in) | Dia (mm) | mm² | cmil | Ω/kft Cu | 60°C | 75°C | 90°C |
|---|---|---|---|---|---|---|---|---|
| 4/0 | 0.4600 | 11.684 | 107.2 | 211600 | 0.049 | 195 | 230 | 260 |
| 3/0 | 0.4096 | 10.404 | 85.0 | 167800 | 0.0618 | 165 | 200 | 225 |
| 2/0 | 0.3648 | 9.266 | 67.4 | 133100 | 0.078 | 145 | 175 | 195 |
| 1/0 | 0.3249 | 8.252 | 53.5 | 105600 | 0.0983 | 125 | 150 | 170 |
| 1 | 0.2893 | 7.348 | 42.4 | 83690 | 0.124 | 110 | 130 | 150 |
| 2 | 0.2576 | 6.544 | 33.6 | 66360 | 0.156 | 95 | 115 | 130 |
| 3 | 0.2294 | 5.827 | 26.7 | 52620 | 0.197 | 85 | 100 | 115 |
| 4 | 0.2043 | 5.189 | 21.2 | 41740 | 0.249 | 70 | 85 | 95 |
| 6 | 0.1620 | 4.115 | 13.3 | 26240 | 0.395 | 55 | 65 | 75 |
| 8 | 0.1285 | 3.264 | 8.37 | 16510 | 0.628 | 40 | 50 | 55 |
| 10 | 0.1019 | 2.588 | 5.26 | 10380 | 0.999 | 30 | 35 | 40 |
| 12 | 0.0808 | 2.053 | 3.31 | 6530 | 1.588 | 20 | 25 | 30 |
| 14 | 0.0641 | 1.628 | 2.08 | 4110 | 2.525 | 15 | 20 | 25 |
| 16 | 0.0508 | 1.291 | 1.31 | 2580 | 4.016 | — | — | — |
| 18 | 0.0403 | 1.024 | 0.823 | 1620 | 6.385 | — | — | — |
| 20 | 0.0320 | 0.812 | 0.518 | 1020 | 10.15 | — | — | — |
| 22 | 0.0254 | 0.644 | 0.326 | 640 | 16.14 | — | — | — |
| 24 | 0.0201 | 0.511 | 0.205 | 404 | 25.67 | — | — | — |
| 26 | 0.0159 | 0.405 | 0.129 | 254 | 40.81 | — | — | — |
| 28 | 0.0126 | 0.321 | 0.081 | 160 | 64.9 | — | — | — |
| 30 | 0.0100 | 0.255 | 0.0509 | 101 | 103.2 | — | — | — |
Ampacity per NEC Table 310.16 — Copper, 3+ current-carrying conductors in raceway/cable. Dash (—) = not rated for building branch circuits.
AWG Formula
dn = 0.005 × 92(36−n)/39 inches
Where n = AWG number (0, 1, 2, … 40). For 00, use n = −1; for 000, n = −2; for 0000, n = −3.
Quick Rules of Thumb
- Every 3 AWG sizes → cross-sectional area doubles
- Every 6 AWG sizes → diameter doubles
- Every 10 AWG sizes → resistance changes by 10×
- Aluminum wire needs to be ~2 AWG sizes larger than copper for equivalent ampacity
Calculate voltage drop for your wire run
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