NEC Wire Sizing

What Size Wire for a Garbage Disposal?

The breaker, copper and aluminum wire, and ground for a typical garbage disposal circuit, with the NEC basis and the nameplate caveats that actually decide it.

Quick answer: A garbage disposal typically needs a 15A / 120V circuit with #14 copper (or #12 aluminum) wire and a #14 copper ground.

Garbage Disposal Circuit Spec

Typical branch circuit for a garbage disposal (nameplate rating)
Voltage120V
Breaker15A
Copper wire#14
Aluminum wire (75°C-marked terminations, SER or conduit)#12
Equipment ground (Cu)#14

A garbage disposal is sized to its nameplate on a dedicated 120V circuit: 15A for most 1/3 to 1/2 HP units, 20A for larger. Confirm whether local practice lets it share the dishwasher circuit. Wire sized at NEC Table 310.16 (copper lead at the 60°C column for NM-B); ground per NEC Table 250.122. The appliance nameplate lists the exact minimum circuit and maximum breaker; it always governs over a typical value.

Aluminum branch conductors are 75°C-rated AA-8000 alloy (SER cable, or XHHW-2 / THWN-2 in conduit); there is no 60°C aluminum NM-B, so the aluminum row uses the 75°C column. Where the terminations are rated 60°C only, size aluminum from the 60°C column instead (#12 here).

Adding this as a new load? Check whether your panel can handle it (the NEC 220.87 service check), or compare it against the breaker size by load chart.


Size Your Exact Circuit

It opens on this page's 15 A circuit at the 60°C column. For a nameplate that differs from the typical value, enter your exact load and conditions. For a long run, the result links to the voltage drop calculator, which checks that wire over your run; this tool does not size for voltage drop.

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Frequently Asked Questions

What size wire do I need for a garbage disposal?

A garbage disposal typically uses a 15A / 120V circuit, which calls for #14 copper (or #12 aluminum) conductors and a #14 copper equipment ground per NEC Table 250.122. A garbage disposal is sized to its nameplate on a dedicated 120V circuit: 15A for most 1/3 to 1/2 HP units, 20A for larger. Confirm whether local practice lets it share the dishwasher circuit.

What size breaker for a garbage disposal?

A 15A single-pole (120V) breaker. The #14 copper conductors are matched to that 15A rating. Do not oversize the breaker to a wire it does not protect: the breaker and the conductor go up together. Always confirm against the appliance nameplate, which lists the exact minimum circuit and maximum overcurrent device.

Can I use aluminum wire for a garbage disposal?

Yes. On the 75C column (the usual basis for aluminum), a 15A circuit needs #12 aluminum, versus #14 copper. Aluminum is common on larger circuits and services to save cost; apply antioxidant to the terminations, torque to the listed spec, and remember aluminum drops slightly more voltage on long runs.


Wire Size for Other Appliances