What Wire Size for 200 Amps?

Minimum Wire Size for 200 Amps (Ampacity Only)

Based solely on NEC Table 310.16 ampacity ratings at 75 degrees C (the most common termination rating), the minimum wire size for 200 amps is 3/0 AWG for copper and 250 kcmil for aluminum. However, these minimums only satisfy the ampacity requirement. For any run longer than a few feet, you must also check voltage drop and may need to upsize the conductor. The tables below show the recommended wire gauge at each distance, accounting for both ampacity and the NEC 3% voltage drop recommendation.

200A Wire Size at 120V by Distance

Recommended wire gauge for a 200-amp, 120-volt, single-phase circuit at each distance. The copper columns show recommendations at both 3% and 5% voltage drop limits. The aluminum column shows the 3% recommendation. At 120 volts, a 3% voltage drop equals 3.6 volts.

200A Wire Size at 240V by Distance

Recommended wire gauge for a 200-amp, 240-volt, single-phase circuit at each distance. The copper columns show recommendations at both 3% and 5% voltage drop limits. The aluminum column shows the 3% recommendation. At 240 volts, a 3% voltage drop equals 7.2 volts.

Common Applications for 200-Amp Circuits

200-amp circuits are used for: Residential main service entrance, large detached structure feeders, commercial branch service, multi-unit residential feeds. Each of these applications may have specific NEC requirements beyond basic wire sizing, including dedicated circuit requirements, GFCI or AFCI protection, disconnect requirements, and specific receptacle configurations. Visit the applications page for detailed guidance on specific circuit types.

When sizing a 200-amp circuit, remember that the NEC requires conductors and overcurrent protection devices to be sized at 125% for continuous loads (loads expected to operate for 3 hours or more). This means a 200-amp breaker can only serve 160 amps of continuous load unless the breaker is specifically rated for 100% continuous duty. If your load is continuous, you may need to upsize to the next standard breaker size, which will also require the corresponding larger wire gauge.

For motor loads on 200-amp circuits, wire sizing follows the special rules in NEC Article 430. Motor branch circuit conductors must be sized at 125% of the motor full-load current from NEC Table 430.248 (single-phase) or Table 430.250 (three-phase), not the motor nameplate current. The branch circuit overcurrent device is sized separately per NEC Table 430.52, which may allow a breaker significantly larger than the conductor ampacity to accommodate motor starting current.

Other Amperage Levels

Browse wire sizing recommendations for other standard amperages. Each page provides complete distance tables for both copper and aluminum at all standard voltages.