1 AWG Wire Specs
Ampacity, geometry, resistance, conduit fill and maximum run length for 1 AWG conductors in copper and aluminium.
Quick answer
1 AWG copper carries about 126 A at 75 °C (107 A at 60 °C, 142 A at 90 °C). The bare conductor is 0.2893 in (7.35 mm) and 83,693 circular mils, with 0.1239 Ω per 1000 ft. It pairs with a 125 A breaker at 75 °C terminations.
Copper 75 °C
126A
Aluminium 75 °C
98A
Diameter
0.2893in
Circular mils
83,693
Full specification
| Size designation | 1 AWG |
|---|---|
| AWG gauge number | 1 |
| Circular mils | 83,693 |
| kcmil | 83.69 |
| Bare diameter (in) | 0.2893 |
| Bare diameter (mm) | 7.348 |
| Cross-section (mm²) | 42.41 |
| THHN/THWN-2 OD (in) | 0.446 |
| Insulated area (sq in) | 0.1562 |
| Copper resistance (Ω/1000 ft) | 0.1239 |
| Aluminium resistance (Ω/1000 ft) | 0.2031 |
| Max standard breaker (Cu, 75 °C) | 125 A |
Published standard — source: Geometry computed from the ASTM B258 AWG formula; resistance from standard resistivityFormula estimate — source: Ampacity from the site model
Ampacity with derating
Estimated ampacity from the 90 °C column at various ambient temperatures and conductor counts.
| Conductors in raceway | 30 °C ambient | 40 °C ambient | 50 °C ambient | 60 °C ambient |
|---|---|---|---|---|
| 3 | 142 A | 130 A | 116 A | 100 A |
| 6 | 114 A | 104 A | 93 A | 80 A |
| 9 | 99 A | 91 A | 81 A | 70 A |
| 15 | 71 A | 65 A | 58 A | 50 A |
| 25 | 64 A | 58 A | 52 A | 45 A |
Source & method: The governing value is also capped by the termination rating, commonly 75 °C, which for this size is 126 A. Run your own conditions.
Maximum run length at 3% voltage drop
One-way distance for 1 AWG copper before drop exceeds 3%.
| Load | 120 V 1Ø | 240 V 1Ø | 208 V 3Ø | 480 V 3Ø |
|---|---|---|---|---|
| 10 A | 1,167 ft | 2,335 ft | 2,337 ft | 5,394 ft |
| 15 A | 778 ft | 1,557 ft | 1,558 ft | 3,596 ft |
| 20 A | 583 ft | 1,167 ft | 1,168 ft | 2,697 ft |
| 30 A | 389 ft | 778 ft | 779 ft | 1,798 ft |
| 40 A | 291 ft | 583 ft | 584 ft | 1,348 ft |
| 50 A | 233 ft | 467 ft | 467 ft | 1,078 ft |
How many 1 AWG conductors fit in conduit
Maximum count of this size alone, at the fill percentage matching the resulting count.
| Conduit | 1/2" | 3/4" | 1" | 1-1/4" | 1-1/2" | 2" | 2-1/2" | 3" | 3-1/2" | 4" |
|---|---|---|---|---|---|---|---|---|---|---|
| EMT | 1 | 1 | 1 | 3 | 5 | 8 | 14 | 22 | 29 | 37 |
| IMC | 1 | 1 | 1 | 4 | 5 | 9 | 13 | 20 | 27 | 34 |
| RMC | 1 | 1 | 1 | 3 | 5 | 8 | 12 | 19 | 25 | 32 |
| PVC Sch 40 | — | 1 | 1 | 3 | 5 | 8 | 12 | 18 | 24 | 32 |
| PVC Sch 80 | — | 1 | 1 | 3 | 4 | 7 | 10 | 16 | 22 | 28 |
Neighbouring sizes
Frequently asked
- How many amps can 1 AWG wire carry?
- 1 AWG copper is estimated at 107 A at 60 °C, 126 A at 75 °C and 142 A at 90 °C, at 30 °C ambient with no more than three current-carrying conductors. Aluminium of the same size is about 98 A at 75 °C.
- What breaker size goes with 1 AWG copper?
- The largest standard overcurrent device that 1 AWG copper supports at 75 °C is 125 A. For a continuous load, the load itself must not exceed 80% of that rating.
- What is the diameter of 1 AWG wire?
- The bare conductor is 0.2893 inches (7.348 mm) in diameter, which is 83,693 circular mils. With THHN/THWN-2 insulation the nominal outside diameter is about 0.446 inches.
- What is the resistance of 1 AWG wire?
- About 0.1239 ohms per 1000 feet for copper and 0.2031 ohms per 1000 feet for aluminium, at 75 °C.
- How far can I run 1 AWG wire?
- Distance depends on load and voltage. At 20 A on a 120 V single-phase circuit, 1 AWG copper stays under 3% voltage drop for about 583 feet one-way. Doubling the voltage roughly doubles the allowable distance.
Materials for this size
Materials for this size
Wire, cable and terminations for 1 AWG.
- THHN/THWN-2 1 AWG copper1 AWG copperBuilding wire in the size this page covers (1 AWG copper).Check price on Amazon →
- NM-B cable 1 AWG1 AWGRomex-type cable for dry indoor branch circuits at this size.Check price on Amazon →
- Wire connectors for 1 AWG1 AWGPush-in or twist-on connectors rated for this conductor size.Check price on Amazon →
- Terminal lugs & anti-oxidantCopper-rated mechanical lugs for panel and disconnect terminations.Check price on Amazon →
Links go to Amazon search results, not a single listing — confirm ratings, insulation type and listing details before buying, and make sure the part is approved for your application.
Related charts & calculators
- Voltage Drop CalculatorPercent drop, end voltage and minimum conductor for any run length.
- Conduit Fill CalculatorFill percentage and maximum conductor count for EMT, RMC, IMC and PVC.
- Breaker Size CalculatorOvercurrent device rating and minimum conductor from load current.
- Wire Ampacity CalculatorDerated ampacity for ambient temperature and bundled conductors.
- Box Fill CalculatorVolume allowances for conductors, clamps, devices and grounds per NEC 314.16.
- Ampacity ChartEstimated allowable ampacity by conductor size, material and insulation rating.