What Size Wire for a 60 Amp Sub Panel 150 Feet Away?
Smallest conductor under 3%
4 AWG
240 volts, single phase, 60 amps, 150 feet one way, 6 AWG copper.
Between 3 and 5 percent. Legal, and still worth fixing on a branch circuit that feeds a motor, a heater or a long lighting run. Going up to 4 AWG brings it under 3 percent.
When the figures look right, the circuit material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.
How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- System voltage240 V
- PhaseSingle phase
- Load current60 A
- One way run length150 ft
- Conductor size6 AWG
- Conductor materialCopper
Voltage drop3.69% on the run
Between 3 and 5 percent. Legal, and still worth fixing on a branch circuit that feeds a motor, a heater or a long lighting run. Going up to 4 AWG brings it under 3 percent.
| Drop | 8.85 V |
|---|---|
| Voltage at the load | 231.2 Vfrom 240 V at the panel |
| Smallest conductor under 3% | 4 AWG |
| Longest run at 6 AWG under 3% | 122 ftone way |
| Conductors to pull | 3including the equipment ground |
The material list this produces
| 6 AWG copper conductor, ft | 495 |
|---|---|
| Conduit or cable, ft | 165 |
| Breaker, 60 A, each | 1 |
| Terminations and lugs, each | 6 |
One way run length compared
Drop is a straight line in length. Double the run and you double the drop, which is why the same wire that is fine in a basement is not fine across a yard.
| One way run length | Voltage drop | Smallest conductor under 3% |
|---|---|---|
| 50 ft | 1.23% on the run | 8 AWG |
| 100 ft | 2.46% on the run | 6 AWG |
| 150 ft | 3.69% on the run | 4 AWG |
| 200 ft | 4.92% on the run | 3 AWG |
| 300 ft | 7.37% on the run | 2 AWG |
What else matters here
Six AWG copper is the ampacity answer for a 60 amp feeder, and over 150 feet it comes out at 3.69 percent, which is past the guideline. Four AWG brings it under.
This is a very common shop or workshop feeder and it is worth thinking about the load before deciding. A 60 amp sub panel feeding a couple of receptacle circuits and some lights will never see 60 amps, and the real drop will be a third of this figure. A 60 amp sub panel feeding a welder or a compressor will see it, at the worst possible moment.
Six AWG holds 3 percent out to 122 feet at this load. If the run is under that, or if the panel is genuinely lightly loaded, 6 AWG is a defensible choice. If there is a motor at the end of it, pull the 4.
What this calculator assumes
- The formula is the standard one: drop equals 2 times K times amps times the one way length, divided by the circular mil area of the conductor. Three phase uses 1.732 in place of the 2.
- K is 12.9 for copper and 21.2 for aluminum, the usual figures for a conductor running warm in conduit. Circular mil areas come from NEC Chapter 9, Table 8.
- Enter the one way distance, not the loop. The formula doubles it for you, because current has to get back.
- The 3 percent branch circuit and 5 percent total figures in 210.19 and 215 are informational notes rather than requirements. Nobody fails an inspection on voltage drop alone, but motors, LED drivers and long well pump runs care a great deal.
Questions people ask
What size wire for a 60 amp sub panel 150 feet away?
4 AWG copper to hold 3 percent. 6 AWG is correct for 60 amps on ampacity and lands at 3.69 percent over that run, which is acceptable on a lightly loaded panel and not on one feeding motors.
How far can 6 AWG carry 60 amps?
About 122 feet at 240 volts before it passes 3 percent drop. Beyond that, 4 AWG.
Can I use aluminum instead?
Yes, and on a long feeder it often saves real money. Aluminum carries about 61 percent of copper's conductivity, so you go up roughly two sizes for the same drop. What matters is the terminations: lugs listed AL or CU-AL, antioxidant compound on the strands, and a torque wrench rather than a feel for it. Aluminum fails at the connection, not in the middle of the run.
The voltage drop calculator takes any dimensions you like and hands back the same list.