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What Size Wire for 175 Amps?

For 175 amps with the displayed 75 C termination defaults, start with 2/0 AWG copper or 4/0 AWG aluminum. This page is the 150-to-200 A service and large-feeder middle step, with tight 75 C margins.
Load
175 A
Distance
0 ft entered
Band
Service / large feeder
Defaults
Non-continuous, 75 C lugs, 86 F, 240 V single-phase
Conductor count
3 current-carrying

Computed Starting Point

The table uses common defaults. Change the calculator inputs for the actual installation.

MaterialComputed sizeOCPDUsable ampacityGoverning constraintDefault check
Copper2/0 AWG175 A175 ATermination rated 75 CPasses defaults
Aluminum4/0 AWG175 A180 ATermination rated 75 CPasses defaults
What Size Wire for 175 Amps? under common non-continuous defaults: THHN or XHHW-2 insulation, 75 C terminations, 86 F ambient, 240 V single-phase, no more than three current-carrying conductors, and 0 ft route length entered.

What 175 A ChangesAt 175 A, the copper row lands exactly on 175 A usable ampacity under the displayed 75 C defaults, while aluminum shows only 180 A. Equipment limited to 60 C will force larger conductors, and service conductor product rules or utility requirements can change the result.

Run the wire size calculator

Adjacent Amp Ratings

See whether stepping one standard size up or down forces a conductor jump under the same defaults.

LoadCopper sizeCopper OCPDAluminum sizeAluminum OCPD
150 A1/0 AWG150 A3/0 AWG150 A
175 A (this page)2/0 AWG175 A4/0 AWG175 A
200 A3/0 AWG200 A250 kcmil200 A
Copper and aluminum starting sizes for 175 A and the neighboring published amp pages, under the same defaults as the result above.

A plateau means neighboring amp ratings share a conductor size under these defaults. A jump means a standard breaker change often needs a larger wire; confirm with your real ambient, length and terminations.

175 A Is the Middle Step Before 200 A

Service / large feeder context for a 175 A circuit.

A 175 A wire-size search usually means a large feeder, service-equipment replacement, shop feed, or panel decision that sits above 150 A but is not intended to become a 200 A service by habit. The rating needs a real load or equipment reason, not just a round-number preference.

Under the displayed 75 C termination defaults, copper moves from 1/0 AWG at 150 A to 2/0 AWG here, and aluminum moves from 3/0 AWG to 4/0 AWG. The next 200 A page moves copper again to 3/0 AWG and aluminum to 250 kcmil.

What Changes This Answer

Checks that can change the starting conductor under the displayed defaults.

  • Do not reuse the 150 A answer

    Under these defaults, 150 A uses 1/0 AWG copper and 3/0 AWG aluminum. This 175 A page moves to 2/0 AWG copper and 4/0 AWG aluminum.

  • Watch the exact copper margin

    The displayed copper row has no extra ampacity above 175 A under 75 C defaults. Derating, long runs, or product limits can move the final size.

  • Check 60 C equipment limits

    The 2/0 AWG copper and 4/0 AWG aluminum results are 75 C defaults. Equipment limited to 60 C will force larger conductors for a full 175 A feeder or service.

  • Compare 200 A before standardizing

    The adjacent 200 A page moves copper to 3/0 AWG and aluminum to 250 kcmil under the same defaults. Do not drift to 200 A without load and equipment support.

  • Confirm service product and utility rules

    Service-entrance cable, raceway conductors, meter lugs, disconnect lugs, utility standards, and AHJ review can all override a generic starting point.

175 Amp Wire Size FAQs

What size wire for 175 amps?
Under the 75 C non-continuous defaults on this page, start with 2/0 AWG copper or 4/0 AWG aluminum. Treat this as a planning starting point only, then confirm the conductor product, terminal rating, load calculation, route length, and utility or AHJ requirements.
Is 175 A the same wire size as 150 A?
No under these defaults. The 150 A page shows 1/0 AWG copper and 3/0 AWG aluminum, while 175 A moves to 2/0 AWG copper and 4/0 AWG aluminum.
Should I use the 200 A page instead?
Only when the load calculation, service equipment, overcurrent device, and utility or AHJ requirements support a 200 A rating. The 200 A page uses larger conductors under these defaults.
Can 2/0 copper be used for every 175 A feeder?
No. It is the displayed 75 C default starting point. Equipment limited to 60 C, derating, voltage drop, or a different conductor product can force a larger conductor.