Wire Gauge Chart (AWG)
American Wire Gauge (AWG) reference chart showing wire diameter in millimeters and inches, plus ampacity ratings for copper and aluminum conductors.
| AWG | Diameter (mm) | Diameter (in) | Copper Amps | Aluminum Amps |
|---|---|---|---|---|
| 0000 (4/0) | 11.684 | 0.4600 | 230 | 180 |
| 000 (3/0) | 10.405 | 0.4096 | 200 | 155 |
| 00 (2/0) | 9.266 | 0.3648 | 175 | 135 |
| 0 (1/0) | 8.251 | 0.3249 | 150 | 120 |
| 1 | 7.348 | 0.2893 | 130 | 100 |
| 2 | 6.544 | 0.2576 | 115 | 90 |
| 3 | 5.827 | 0.2294 | 100 | 75 |
| 4 | 5.189 | 0.2043 | 85 | 65 |
| 6 | 4.115 | 0.1620 | 65 | 50 |
| 8 | 3.264 | 0.1285 | 50 | 40 |
| 10 | 2.588 | 0.1019 | 35 | 30 |
| 12 | 2.053 | 0.0808 | 25 | 20 |
| 14 | 1.628 | 0.0641 | 20 | 15 |
| 16 | 1.291 | 0.0508 | 13 | 10 |
| 18 | 1.024 | 0.0403 | 10 | 7 |
| 20 | 0.812 | 0.0320 | 7 | 5 |
| 22 | 0.644 | 0.0253 | 5 | 3 |
| 24 | 0.511 | 0.0201 | 3.5 | 2 |
| 26 | 0.405 | 0.0159 | 2.2 | 1.3 |
| 28 | 0.321 | 0.0126 | 1.4 | 0.8 |
| 30 | 0.255 | 0.0100 | 0.9 | 0.5 |
How to Read This Chart
Find the AWG size in the left column. The diameter columns show the physical wire size. The ampacity columns show the maximum recommended current for copper and aluminum conductors based on standard NEC 60°C insulation ratings. Actual ampacity depends on insulation type, ambient temperature, and number of conductors in a raceway.
Frequently Asked Questions
What does AWG mean?
AWG stands for American Wire Gauge, a standardized system for measuring the diameter of electrically conducting wire. The gauge number is inversely proportional to the wire diameter — a lower AWG number indicates a thicker wire.
What size wire do I need for a 20-amp circuit?
A 20-amp residential circuit typically requires 12 AWG copper wire, which has an ampacity of 25 amps with a standard 60°C insulation rating. Always follow local electrical codes.
Can I use aluminum wire instead of copper?
Yes, but aluminum wire must be larger than copper for the same ampacity. For example, where 12 AWG copper handles 25 amps, you would need 10 AWG aluminum for a 20-amp circuit. Aluminum also requires special connectors rated for aluminum.
What is the difference between stranded and solid wire of the same gauge?
Solid and stranded wire of the same AWG have the same total cross-sectional copper area and the same ampacity rating. Stranded wire is more flexible and easier to route, while solid wire holds its shape better for termination.