Wire size for a 60 amp breaker
| Wire | Condition | Minimum size for 60 A |
|---|---|---|
| Copper | NM-B (Romex) cable or 60°C terminals | 4 AWG |
| Copper | THHN/THWN in conduit, 75°C terminals | 6 AWG |
| Aluminum | 75°C terminals | 4 AWG |
| Aluminum | 60°C terminals | 3 AWG |
6 AWG copper is rated 55 A in the 60°C column, 65 A at 75°C and 75 A at 90°C. The size above is the smallest whose ampacity is at least 60 A. Most modern breakers and panels have 75°C terminals, but a 60 A circuit is presumed 60°C unless the equipment is marked otherwise (NEC 110.14(C)).
Voltage drop: how far can 6 AWG run at 60 A?
The 6 AWG above carries 60 A safely but loses voltage over distance. At the full 60 A and 240 V, 6 AWG copper stays within the NEC's 3% recommendation for about 122 ft one way. 4 AWG stretches that to 194 ft.
| One-way distance | 6 AWG copper | 4 AWG copper | 3 AWG copper |
|---|---|---|---|
| 25 ft | 0.6% | 0.4% | 0.3% |
| 50 ft | 1.2% | 0.8% | 0.6% |
| 100 ft | 2.5% | 1.5% | 1.2% |
| 150 ft | 3.7% | 2.3% | 1.8% |
| 200 ft | 4.9% | 3.1% | 2.5% |
Percent drop at 60 A and 240 V.
On 120 V circuits, the 60 A percentages are twice these values.
Check your own 60 A run with the voltage drop calculator, or let the wire size calculator choose the size for you.
What a 60 amp circuit is used for
- Sub panels in garages and workshops
- Level 2 EV chargers drawing 48 A continuous
- Large hot tubs and electric furnaces
- Air-conditioning condensers and heat pumps
Cable type matters
NM-B for a 60 A circuit must be 4 AWG, since 6 AWG is only 55 A in the 60°C column. 6 AWG THHN in conduit is rated 65 A at 75°C, which is why electricians pull 6 AWG wire to a 60 A sub panel. Terminals must be rated 75°C.
Continuous loads and common mistakes
On a 60 A breaker, a continuous load running three hours or more should not exceed 80% of the rating. That is 48 A, or about 11,520 W at 240 V. At 60 A, check that the terminals on both the breaker and the panel are marked 75°C before using 6 AWG. If they are marked 60°C, use 4 AWG.
For a 60 A breaker the ground wire comes from NEC Table 250.122. Use the ground wire size calculator. For other breaker sizes, see the breaker to wire size chart, or jump to 20 amps, 30 amps, 40 amps, 50 amps, 100 amps.
Frequently asked questions
What size wire for a 60 amp breaker?
6 AWG copper at 75°C terminals, or 4 AWG for NM-B cable. In aluminum use 4 AWG.
How far can 6 AWG wire run on 60 amps?
About 122 feet one way at 240 V before the voltage drop passes the NEC's 3% recommendation. Past that distance, step up to 4 AWG.
What size wire for a 60 amp sub panel?
6 AWG copper in conduit on 75°C terminals, or 4 AWG for NM-B cable. For long runs, step up for voltage drop.
What size wire for a 48 amp EV charger?
6 AWG copper on a 60 A breaker, since 48 × 1.25 = 60 A.