10 AWG Wire Specs
Ampacity, geometry, resistance, conduit fill and maximum run length for 10 AWG conductors in copper and aluminium.
Quick answer
10 AWG copper carries about 32 A at 75 °C (27 A at 60 °C, 37 A at 90 °C). The bare conductor is 0.1019 in (2.59 mm) and 10,383 circular mils, with 0.9988 Ω per 1000 ft. It pairs with a 30 A breaker at 75 °C terminations.
Copper 75 °C
32A
Aluminium 75 °C
25A
Diameter
0.1019in
Circular mils
10,383
Full specification
| Size designation | 10 AWG |
|---|---|
| AWG gauge number | 10 |
| Circular mils | 10,383 |
| kcmil | 10.38 |
| Bare diameter (in) | 0.1019 |
| Bare diameter (mm) | 2.588 |
| Cross-section (mm²) | 5.26 |
| THHN/THWN-2 OD (in) | 0.164 |
| Insulated area (sq in) | 0.0211 |
| Copper resistance (Ω/1000 ft) | 0.9988 |
| Aluminium resistance (Ω/1000 ft) | 1.6373 |
| Max standard breaker (Cu, 75 °C) | 30 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 | 37 A | 34 A | 30 A | 26 A |
| 6 | 30 A | 27 A | 24 A | 21 A |
| 9 | 26 A | 24 A | 21 A | 18 A |
| 15 | 19 A | 17 A | 15 A | 13 A |
| 25 | 17 A | 15 A | 14 A | 12 A |
Source & method: The governing value is also capped by the termination rating, commonly 75 °C, which for this size is 32 A. Run your own conditions.
Maximum run length at 3% voltage drop
One-way distance for 10 AWG copper before drop exceeds 3%.
| Load | 120 V 1Ø | 240 V 1Ø | 208 V 3Ø | 480 V 3Ø |
|---|---|---|---|---|
| 10 A | 144 ft | 289 ft | 289 ft | 669 ft |
| 15 A | 96 ft | 193 ft | 193 ft | 446 ft |
| 20 A | 72 ft | 144 ft | 144 ft | 334 ft |
| 30 A | 48 ft | 96 ft | 96 ft | 223 ft |
| 40 A | 36 ft | 72 ft | 72 ft | 167 ft |
| 50 A | 28 ft | 57 ft | 57 ft | 133 ft |
How many 10 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 | 5 | 10 | 16 | 28 | 38 | 63 | 110 | 167 | 218 | 279 |
| IMC | 6 | 11 | 18 | 31 | 42 | 68 | 97 | 150 | 200 | 258 |
| RMC | 5 | 10 | 16 | 28 | 39 | 64 | 92 | 142 | 189 | 243 |
| PVC Sch 40 | 5 | 9 | 15 | 27 | 37 | 62 | 88 | 137 | 184 | 237 |
| PVC Sch 80 | 4 | 7 | 13 | 23 | 32 | 54 | 77 | 121 | 164 | 213 |
Neighbouring sizes
Frequently asked
- How many amps can 10 AWG wire carry?
- 10 AWG copper is estimated at 27 A at 60 °C, 32 A at 75 °C and 37 A at 90 °C, at 30 °C ambient with no more than three current-carrying conductors. Aluminium of the same size is about 25 A at 75 °C.
- What breaker size goes with 10 AWG copper?
- The largest standard overcurrent device that 10 AWG copper supports at 75 °C is 30 A. For a continuous load, the load itself must not exceed 80% of that rating.
- What is the diameter of 10 AWG wire?
- The bare conductor is 0.1019 inches (2.588 mm) in diameter, which is 10,383 circular mils. With THHN/THWN-2 insulation the nominal outside diameter is about 0.164 inches.
- What is the resistance of 10 AWG wire?
- About 0.9988 ohms per 1000 feet for copper and 1.6373 ohms per 1000 feet for aluminium, at 75 °C.
- How far can I run 10 AWG wire?
- Distance depends on load and voltage. At 20 A on a 120 V single-phase circuit, 10 AWG copper stays under 3% voltage drop for about 72 feet one-way. Doubling the voltage roughly doubles the allowable distance.
Materials for this size
Materials for this size
Wire, cable and terminations for 10 AWG.
- THHN/THWN-2 10 AWG copper10 AWG copperBuilding wire in the size this page covers (10 AWG copper).Check price on Amazon →
- NM-B cable 10 AWG10 AWGRomex-type cable for dry indoor branch circuits at this size.Check price on Amazon →
- Wire connectors for 10 AWG10 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.