How many amps can 10 AWG wire carry?
35 A — copper at 75 °C, NEC Table 310.16.
10 AWG copper carries 35 A at 75 °C, 30 A at 60 °C and 40 A at 90 °C under NEC Table 310.16, before derating. NEC 240.4(D) then caps the breaker at 30 A, so 30 A is the usable answer. Aluminum at the same size is 30 A at 75 °C.
Safety first. These figures are an educational reference before derating, not a code substitute. Verify against the current NEC and have circuits reviewed by a licensed electrician.
10 AWG ampacity — copper vs aluminum
| Material | 60 °C | 75 °C | 90 °C | Breaker cap |
|---|---|---|---|---|
| Copper | 30 A | 35 A | 40 A | 30 A |
| Aluminum | 25 A | 30 A | 35 A | 25 A |
Values are amps at a 30 °C ambient, before derating for temperature or conductor bundling. Most installations must use the 75 °C column regardless of the wire's own rating, because terminals and breakers are rated 75 °C (NEC 110.14(C)).
How far can you run 10 AWG at 30 A?
Ampacity answers whether a conductor will overheat. It says nothing about whether the voltage still arrives at the far end. Past roughly fifty feet, voltage drop is usually what really sets the wire size. These are the longest one-way runs that keep drop within the 3% recommended by the NEC 210.19(A) informational note, for 10 AWG copper carrying 30 A.
| System | Typical use | Max run at 3% | Drop at 100 ft |
|---|---|---|---|
| 120 V | standard receptacle and lighting circuits | 60 ft | 5.99 V |
| 240 V | ranges, dryers, EV chargers, feeders | 120 ft | 5.99 V |
| 12 V DC | automotive, marine, solar and battery runs | 6 ft | 5.99 V |
Single-phase, one-way distance, copper at 20 °C. Aluminum reaches its limit at roughly 60% of these distances for the same size. The 3% figure is a recommendation in an informational note, not a code requirement.
10 AWG wire size — diameter, area and resistance
Diameter
0.1019 in · 2.588 mm
Cross-section
5.261 mm² · 10,383 cmil
Nearest metric size
6 mm² (rounds up)
Copper resistance
0.9988 Ω per 1000 ft @ 20 °C
Aluminum resistance
1.6681 Ω per 1000 ft
Area
10.383 kcmil
Diameter is computed from the ASTM B258 definition d = 0.005 × 92^((36 − n)/39), not read from a rounded table. Resistance uses the annealed-copper constant 10.371 Ω·cmil/ft at 20 °C.
What 10 AWG wire is used for
- 30 A circuits
- electric dryers and water heaters
- A/C condensers, well pumps
The 10 gauge mistake worth knowing
10 AWG copper shows 35 A at 75 °C, but NEC 240.4(D) caps its breaker at 30 A regardless. There is no 35 A residential circuit on 10 AWG — the table value simply cannot be used.