Wire & Watts

What size wire for 60 amps at 200 feet?

Updated by Biel Vazquez

Short answer: For a 60 amp load 200 feet away (one way) at 240 V, use 3 AWG copper or 1 AWG aluminum in conduit with 75 °C terminations, which keeps voltage drop at 2.5% and 2.5%. In NM-B (Romex) cable it is 3 AWG copper. The breaker stays 60 A; the extra size is only for distance.

60 amps at 200 feet: wire size by type

240 V single phase, 60 A load on a 60 A breaker, 200 ft one way, 30 °C ambient. Computed with our wire size calculator.
Wire typeSize by ampacitySize for 200 ft (≤3% drop)Voltage drop
Copper THHN/THWN-2 in conduit, 75 °C6 AWG3 AWG2.45%
Aluminum XHHW-2 in conduit, 75 °C4 AWG1 AWG2.53%
Copper NM-B (Romex) cable, 60 °C4 AWG3 AWG2.45%
Aluminum SER / NM-B cable, 60 °C3 AWG1 AWG2.53%

That is one or more sizes above the 6 AWG that ampacity alone allows: at 200 ft the run, not the breaker, decides the gauge. NEC 250.122(B) then requires the equipment ground to be increased in proportion: start from 10 AWG copper for a 60 A breaker.

Voltage drop of each gauge over 200 ft

Copper, 240 V, resistance from NEC Chapter 9 Table 8 at 75 °C. The current travels out and back, so the wire length is twice the run.
WireVolts lost at 60 ADrop at 60 ADrop at 48 A (80%)
6 AWG copper11.78 V4.91%3.93%
4 AWG copper7.39 V3.08%2.46%
3 AWG copper5.88 V2.45%1.96%
2 AWG copper4.66 V1.94%1.55%
1 AWG copper3.70 V1.54%1.23%
voltage drop = 2 × length × resistance per 1,000 ft × amps ÷ 1,000
            = 2 × 200 × R(3 AWG) × 60 ÷ 1,000 = 5.88 V
percent     = 5.88 ÷ 240 × 100 = 2.45%

If the real load is the 80% continuous maximum (48 A, as with an EV charger on a 60 A breaker), copper in conduit can be 4 AWG. 3% is the NEC's recommendation for a branch circuit (Informational Note to 210.19), not a hard rule, but motors, compressors and chargers run better with it.

Same 60 A, other distances

50 ft · 75 ft · 100 ft · 150 ft. Minimum sizes with no distance correction: what size wire for a 60 amp breaker.

Other loads at 200 feet

30 A · 40 A · 50 A · 100 A · 125 A · 150 A · 200 A

Change the numbers in the calculator

Safety. A 60 A circuit or feeder over 200 ft needs a permit almost everywhere in the US. Buried runs have their own depth and conduit rules (NEC 300.5), and equipment nameplates override any general table.

Keep reading

Sources: NFPA 70 (NEC), NEC Chapter 9, Table 8: conductor properties. Method and tables: methodology.