What Size Wire for 50 Amps? Complete Guide

Wire Size for 50 Amps

Wire MaterialSize (Standard)Size (Continuous Load)Ampacity
Copper (60°C)6 AWG4 AWG55A / 70A
Copper (75°C)6 AWG4 AWG65A / 85A
Aluminum (60°C)4 AWG2 AWG55A / 75A
Aluminum (75°C)4 AWG2 AWG65A / 90A

Frequently Asked Questions

What size wire for 50 amps?

6 AWG copper wire is rated for 55 amps at 60°C (NEC Table 310.16), suitable for 50-amp breakers. For continuous loads: 50A × 1.25 = 62.5A → use 4 AWG copper (70A rated).

Can I use 8 AWG wire on a 50 amp breaker?

No. 8 AWG is rated for only 40 amps. Using it on a 50-amp breaker violates NEC 240.4. Use 6 AWG minimum for 50 amps.

What uses a 50 amp circuit?

50-amp circuits are used for: electric ranges/ovens, large AC units (4-5 ton), hot tubs, RV hookups, and EV chargers. Most require 240V with 6 AWG copper wire.

Disclaimer: For preliminary design only. Verify against local codes and professional engineering requirements.