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What Size Breaker for 2 AWG Wire?

For 2 AWG wire under the displayed non-receptacle defaults, the largest common breaker is 125 A for copper and 90 A for aluminum. The copper result is a next-size-up breaker-protection limit, not proof that the conductor can carry a full 125 A design load.
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Breaker Starting Point

Maximum common breaker sizes under common conditions. Derating or receptacle limits can reduce these.

MaterialConductorLargest common breakerAssumptions
Copper2 AWG copper125 A90 C insulation, 75 C lugs, 86 F, 3 current-carrying conductors, non-receptacle circuit default
Aluminum2 AWG aluminum90 A90 C insulation, 75 C lugs, 86 F, 3 current-carrying conductors, non-receptacle circuit default
What Size Breaker for 2 AWG Wire? under common non-receptacle defaults: 90 C insulation, 75 C lugs, 86 F ambient, no more than three current-carrying conductors, and next-size-up checks only where eligible.

What 2 AWG ChangesAt 2 AWG, the copper maximum is a next-size-up result, not a plain ampacity match. If next-size-up is unavailable, if the equipment is 60 C only, or if aluminum is installed, the displayed 125 A copper answer can be too high for the real feeder.

Check breaker and wire together

Adjacent Wire Sizes

See whether stepping one conductor size changes the maximum standard breaker.

WireCopper max breakerAluminum max breaker
3 AWG100 A80 A
2 AWG (this page)125 A90 A
1 AWG150 A100 A
Largest common breakers for 2 AWG and neighboring published wire sizes under the same defaults.

2 AWG Is a 125 A Copper Caution Point

Large feeder context for 2 AWG wire.

A 2 AWG breaker-size search often comes from a planned feeder, a panelboard upgrade, or a conductor found during a service-adjacent project. The search can sound like a load-sizing question, but this page is only checking conductor protection under the displayed defaults.

Under the displayed defaults, 2 AWG copper has 115 A usable ampacity at 75 C and reaches a 125 A breaker through the non-receptacle next-size-up path. 2 AWG aluminum lands at 90 A, so the material choice changes the answer sharply.

Field Checks for This Wire Size

Checks that matter in this conductor band — not a generic breaker list.

  • Name the next-size-up step

    The 125 A copper maximum depends on the page's non-receptacle next-size-up default from 115 A usable ampacity. It is a breaker-protection ceiling, not a 125 A load rating.

  • Check the actual load

    A feeder load that truly needs 125 A of ampacity can require a larger conductor. Run the load calculation before treating this breaker maximum as a usable design.

  • Do not make aluminum 100 A

    Under these defaults, 2 AWG aluminum returns a 90 A maximum breaker. Do not round it to 100 A from habit or from a copper chart.

  • Check 60 C terminals

    Some equipment can limit terminations to 60 C. That changes the conductor ampacity before the breaker maximum is selected.

  • Use equipment instructions first

    Panelboards, disconnects, and listed equipment can publish conductor ranges, material limits, and maximum overcurrent values that are more specific than this generic page.

2 AWG Breaker FAQs

What size breaker for 2 AWG wire?
Under the displayed non-receptacle defaults on this page, 2 AWG copper has a 125 A maximum breaker and 2 AWG aluminum has a 90 A maximum breaker.
Why does 2 AWG copper show 125 A?
The 75 C ampacity path lands at 115 A, which is not a standard breaker rating. With the page's non-receptacle default, the next-size-up path reaches 125 A.
Is 2 AWG aluminum enough for a 100 A breaker?
Not under the displayed defaults. The 2 AWG aluminum row returns a 90 A maximum breaker, so a 100 A aluminum result needs a larger conductor or different verified conditions.
Can I use the 1 AWG page instead?
Only when the load calculation, equipment lugs, material, terminal temperature, and circuit type support moving to the next conductor size.
Can I use this page as final approval for a 2 AWG feeder?
No. Treat it as a compatibility starting point only. Feeder work still needs load calculation, terminal temperature, conductor material, raceway fill, voltage drop, equipment listings, and AHJ review.