The direct answer for the 2 AWG amp rating depends on your conductor material and the temperature rating of your terminations. Based on the 75°C column of NEC Table 310.16, 2 AWG copper wire is rated for 115 amps, and 2 AWG aluminum wire is rated for 90 amps. These baseline figures assume an ambient temperature of 30°C (86°F) and no more than three current-carrying conductors in a raceway.

While 2 AWG is a heavy-duty conductor commonly used for 100-amp subpanel feeders, large EV charging circuits, and high-capacity solar inverter runs, simply memorizing the base number is not enough to pass an inspection or prevent a fire. You must understand which temperature column applies to your specific hardware, how ambient heat derates your wire, and the physical limitations of the lugs you are terminating into.

The Master 2 AWG Ampacity Table (NEC Table 310.16)

The following data is extracted directly from the NFPA 70 National Electrical Code (NEC), specifically Table 310.16. This table serves as the foundational reference for sizing conductors rated 0-2000 volts.

Table 1: 2 AWG Ampacity Ratings per NEC Table 310.16 (30°C Ambient, Max 3 Current-Carrying Conductors)
Wire Material Common Insulation Types 60°C Column (Amps) 75°C Column (Amps) 90°C Column (Amps)
Copper THHN / THWN-2 95A 115A 130A
Copper XHHW-2 95A 115A 130A
Aluminum / CCA THHN / THWN-2 75A 90A 100A
Aluminum / CCA XHHW-2 75A 90A 100A
How to Read This Table: The columns represent the maximum temperature the wire insulation and the termination hardware can safely withstand. The rows differentiate between copper and aluminum. Modern building wire like THHN/THWN-2 and XHHW-2 is manufactured with 90°C insulation, but as explained below, you rarely get to use the 90°C column for your final breaker sizing.

Bookmark Quick-Jump: Most Queried 2 AWG Scenarios

  • 100-Amp Subpanel Feeder (Aluminum): Use 2 AWG Aluminum XHHW-2 or THHN. Rated at 90A in the 75°C column, which is the standard rating for panel lugs. (Note: For a full 100A load, many electricians step up to 1/0 AWG Aluminum, but 2 AWG is legally sufficient for calculated loads under 90A or when protected by a 90A breaker).
  • 100-Amp Subpanel Feeder (Copper): Use 2 AWG Copper. Rated at 115A in the 75°C column, providing ample headroom for a 100A main breaker.
  • Welding Receptacle (50A-60A Breaker): 2 AWG is frequently pulled for long runs to 50A or 60A welder outlets to mitigate voltage drop, utilizing the 115A/90A capacity with massive thermal overhead.

Which Temperature Column Applies to Your Installation?

The most common mistake DIYers and junior apprentices make is looking at the 90°C rating of THHN wire (130A for copper) and assuming they can protect it with a 125A breaker. This violates NEC 110.14(C), which governs termination provisions. For a deep dive on this rule, refer to this EC&M breakdown of termination temperature limits.

The rule is simple: The ampacity of the circuit is limited by the lowest temperature rating of any connected component.

  • The 60°C Column: Applies to circuits rated 100 amps or less if the equipment is not marked with a temperature rating, or if you are using older NM-B (Romex) cable. However, 2 AWG NM-B is exceptionally rare and generally not manufactured for standard residential use.
  • The 75°C Column: This is your default for almost all modern residential and commercial 2 AWG installations. Standard breakers, panelboard lugs, and disconnect switches are factory-rated for 75°C terminations. Therefore, even though your 2 AWG THHN copper wire has 90°C insulation, you must use the 75°C column (115A) to determine your maximum overcurrent protection.
  • The 90°C Column: You are only permitted to use this column for derating calculations (adjusting for heat and bundling) or if every single piece of hardware in the circuit—from the breaker to the lugs to the busbar—is explicitly stamped and listed for 90°C, which is virtually nonexistent in standard sub-200A residential gear.

Derating Factors: When 115A Isn't Really 115A

The baseline values in Table 310.16 assume a perfect environment: 30°C (86°F) ambient air and no more than three current-carrying conductors bundled together. Real-world jobsites rarely offer perfect conditions. When conditions change, you must apply correction and adjustment factors to the 90°C column before comparing the result to your 75°C termination limit.

Ambient Temperature Correction

If you are routing 2 AWG THHN copper through a hot attic in the middle of summer, the ambient temperature easily exceeds 30°C. Let's run the math for an attic measured at 110°F (43°C).

  1. Locate the 90°C column for 2 AWG Copper: 130A.
  2. Find the correction factor for 41-45°C in NEC Table 310.15(B)(1): 0.87.
  3. Multiply: 130A × 0.87 = 113.1A.

Because 113.1A is still greater than the 75°C termination limit of 115A (wait, 113.1A is slightly less than 115A), your derated ampacity drops to 113.1A. While you can still legally use this on a 100A breaker, you have lost your thermal headroom. If the attic reaches 122°F (50°C), the factor drops to 0.82 (130 × 0.82 = 106.6A), pushing you dangerously close to the trip curve of a 100A breaker under continuous load.

Conductor Bundling Adjustment

If you pull two 2 AWG copper circuits (4 current-carrying conductors total) through the same conduit, you must apply an 80% adjustment factor to the 90°C column.

  • 130A × 0.80 = 104A.

Since 104A is less than the 75°C termination rating of 115A, your new maximum ampacity is 104A. You must protect this wire with a breaker rated at or below 104A (the next standard size down is 100A).

What the Ampacity Table Cannot Tell You

Ampacity tables only address thermal limits—the point at which the wire insulation begins to degrade and melt. They do not account for electrical efficiency, physical fit, or continuous load rules.

Voltage Drop Over Distance

NEC Table 310.16 does not calculate voltage drop. If you are feeding a detached garage 150 feet away with a 100A subpanel using 2 AWG aluminum, your wire is thermally safe at 90A. However, pulling a continuous 80A load across 150 feet of 2 AWG aluminum will result in a voltage drop of roughly 4.5% on a 240V circuit. This exceeds the NEC informational recommendation of 3% for feeders. Your tools will run hot, lights will dim, and electronics may brown out. For a 150-foot run at 100A, you must upsize to 1/0 AWG or even 2/0 AWG aluminum to maintain voltage stability, regardless of the thermal ampacity table.

Continuous vs. Non-Continuous Loads

If your 2 AWG wire is feeding a load that will run for 3 hours or more (like an EV charger or a commercial lighting panel), NEC Article 210 requires you to derate the overcurrent device by 125%. A wire with a base ampacity of 115A (Copper, 75°C) can only be loaded to 92A continuously. If you are wiring a continuous 100A load, 2 AWG copper is insufficient; you must step up to 1 AWG or 1/0 AWG.

Physical Lug Limitations

Finally, the table assumes you can physically terminate the wire. 2 AWG wire is thick and stiff. Standard 50A or 60A breakers often feature lug cavities designed for a maximum of 6 AWG or 4 AWG wire. Forcing a 2 AWG conductor into an undersized lug by trimming strands compromises the connection, increases resistance, and creates a severe fire hazard. Always verify the manufacturer's datasheet for the specific breaker or terminal block to ensure it is physically rated to accept a 2 AWG conductor before purchasing your wire.