What size circuit does a dishwasher need?

Whatever its rating plate and installation manual say, which is why we do not publish a figure. Two dishwashers of the same size can differ by several amps depending on the heating element and dry cycle. Read the plate, enter the figure here, and check the manual for whether a dedicated circuit is required — that requirement is a common cause of failed inspections.

Why will you not publish a table of typical appliance circuits?

Because such a table is a guess about a machine we have not seen, and the consequences of guessing low are not academic. Every appliance carries its actual figures on a rating plate, and the manufacturer publishes an installation manual with a specification the Code gives weight to. A generic table competes with both and loses to both.

How do I convert watts to amps?

Divide watts by volts. A 1,500 W appliance on a 120 V circuit draws 12.5 A. The tool does this for you, but it is worth knowing because it is the whole conversion. If your plate gives both watts and amps and they disagree slightly, use the amps figure.

What is the 125% rule and when does it apply?

A load that runs at or near full draw for three hours or more is a continuous load, and it is sized at 125% of nameplate. Most motor loads are treated the same way. The practical consequence is that a 16 A continuous load needs 20 A of circuit, so it fills a 20 A circuit entirely rather than sitting comfortably on it.

What does "dedicated circuit" mean?

A circuit serving that appliance and nothing else — no receptacles, no lighting, no second appliance. Many appliances require one, and the requirement usually appears in the installation manual rather than on the rating plate. It is one of the most common reasons an otherwise correct installation fails inspection.

My appliance plate says "minimum circuit ampacity". Do I still need this tool?

No, and that is the good outcome. Where a manufacturer prints a minimum circuit ampacity and a maximum overcurrent protective device, those figures are the specification and no conversion is needed. Take them straight to the wire size question.

Does this tell me whether my panel can take it?

No. That is a separate question about spare capacity and physical spaces, which are different things. Our panel space checker covers the slots and the load calculator covers the capacity.

HyreElectrical tools

What circuit this appliance needs, from its plate, not a category

We publish no table of typical appliance circuits, because two machines of the same kind can differ by several amps and a table cannot know which you bought. Yours has the answer printed on it.

The plate not a table on the internet Rating plates give volts and either amps or watts. Where a manufacturer prints a minimum circuit ampacity and a maximum overcurrent device, those are the answer outright. The Code requires listed equipment to be installed in accordance with its instructions, so the manual outranks any generic table — including any we could publish.

Enter the nameplate amps, or the watts and the voltage, and say whether the load is motor-driven or continuous. The tool converts to amps, applies the 125% factor where it belongs, and points to the standard device size a circuit like that commonly lands on.

Then follow the chain. This establishes the ampacity; the wire size calculator turns that into a conductor, and the voltage drop calculator checks whether the run length forces a larger one. Live electrical work is not a do-it-yourself subject here. Nothing on this site instructs a reader to open, probe or modify energised equipment.

From the rating plate

Amps if you have them, watts and volts if you do not. Nothing is emailed.

— Circuit it points to

— Common device size

— Sharing

— Load

— Why that factor

— Next question

What this assumed —

Indicative. The manufacturer’s installation instructions are the specification, and they carry code weight. Not instructions to perform electrical work.

The nameplate is the authority, not a category

Every "typical circuit for a dishwasher" table on the internet is a guess about a machine the writer has never seen. Yours has the answer printed on it.

We do not publish a table of appliance circuits, and you should be wary of ones that do. Two dishwashers of the same size can differ by several amps depending on whether they have a heating element, a booster, or a fan-assisted dry cycle. A category table cannot know which you bought. The rating plate can.

Find the plate before anything else. It is a sticker or stamped panel, usually on the back, on the door jamb, inside the door, or on the underside. It gives volts and either amps or watts. If it gives watts, divide by volts to get amps — that is the whole conversion and this tool does it for you.

Manufacturer instructions carry code weight. The installation manual frequently specifies a circuit, and the Code requires listed equipment to be installed in accordance with its instructions. Where the manual and a generic table disagree, the manual wins — and the manual is free to download.

Motor-driven and continuous loads are sized at 125%. A load that runs at or near full draw for three hours or more, and most motor loads, are sized above nameplate rather than at it. That is why a 16 A continuous load does not sit comfortably on a 20 A circuit — it needs 20 A of capacity for a 16 A draw and has none spare.

Nothing on this site is a stamped load calculation, a design, or a permit document. A load calculation that an inspector accepts is produced by someone who has seen the building and signs for it. This screens what a circuit is likely to need so you can follow a quote or check a plan. Live electrical work is not a do-it-yourself subject here. Nothing on this site instructs a reader to open, probe or modify energised equipment.

Reading a rating plate

Six things that are on it, and what each one changes.

Volts — 120 or 240
The single biggest fork. A 240 V appliance needs a two-pole breaker and a different circuit entirely, and at the same wattage it draws half the current of a 120 V equivalent.
Amps, or watts to convert
Amps is the figure the circuit is sized from. If only watts is given, divide by volts. If both are given and disagree slightly, use the amps.
Whether it says "minimum circuit ampacity"
Some equipment — notably HVAC and some appliances — prints a minimum circuit ampacity and a maximum overcurrent device directly. Where those appear they are the answer and no calculation is needed.
Whether a dedicated circuit is specified
Many appliances require one, meaning nothing else may share it. This is usually in the installation manual rather than on the plate, and it is a common source of failed inspections.
Whether it is motor-driven
Compressors, pumps and fans draw a surge on start that a resistive load does not, and are sized at 125%. The plate will often show a locked-rotor or LRA figure alongside the running amps.
Model number, for the manual
Download the installation manual. It is free, it is specific to your machine, and where it specifies a circuit that specification carries code weight.

Circuit sizing asks three questions, and this tool answers the first

Circuit sizing is a chain and each link can change the answer. This page covers the first; the other two have their own tools.

Question	What decides it	Where
1. What ampacity does the circuit need?	The nameplate, plus 125% if the load is continuous or motor-driven, plus whatever the installation manual specifies.	This page
2. What conductor carries that?	NEC Table 310.16, capped by the 240.4(D) small-conductor rule and by the termination temperature under 110.14(C).	Wire size calculator
3. Does the run length force a larger one?	Voltage drop over the distance. A long run can require a bigger conductor than ampacity alone would.	Voltage drop calculator
4. Is there room in the panel?	Physical spaces and available capacity, which are different things.	Panel space checker and load calculator

Questions this calculator answers

What size circuit does a dishwasher need?: Whatever its rating plate and installation manual say, which is why we do not publish a figure. Two dishwashers of the same size can differ by several amps depending on the heating element and dry cycle. Read the plate, enter the figure here, and check the manual for whether a dedicated circuit is required — that requirement is a common cause of failed inspections.
Why will you not publish a table of typical appliance circuits?: Because such a table is a guess about a machine we have not seen, and the consequences of guessing low are not academic. Every appliance carries its actual figures on a rating plate, and the manufacturer publishes an installation manual with a specification the Code gives weight to. A generic table competes with both and loses to both.
How do I convert watts to amps?: Divide watts by volts. A 1,500 W appliance on a 120 V circuit draws 12.5 A. The tool does this for you, but it is worth knowing because it is the whole conversion. If your plate gives both watts and amps and they disagree slightly, use the amps figure.
What is the 125% rule and when does it apply?: A load that runs at or near full draw for three hours or more is a continuous load, and it is sized at 125% of nameplate. Most motor loads are treated the same way. The practical consequence is that a 16 A continuous load needs 20 A of circuit, so it fills a 20 A circuit entirely rather than sitting comfortably on it.
What does "dedicated circuit" mean?: A circuit serving that appliance and nothing else — no receptacles, no lighting, no second appliance. Many appliances require one, and the requirement usually appears in the installation manual rather than on the rating plate. It is one of the most common reasons an otherwise correct installation fails inspection.
My appliance plate says "minimum circuit ampacity". Do I still need this tool?: No, and that is the good outcome. Where a manufacturer prints a minimum circuit ampacity and a maximum overcurrent protective device, those figures are the specification and no conversion is needed. Take them straight to the wire size question.
Does this tell me whether my panel can take it?: No. That is a separate question about spare capacity and physical spaces, which are different things. Our panel space checker covers the slots and the load calculator covers the capacity.
Can I use this to add a circuit myself?: No. Live electrical work is not a do-it-yourself subject here. Nothing on this site instructs a reader to open, probe or modify energised equipment. Nothing on this site is a stamped load calculation, a design, or a permit document. A load calculation that an inspector accepts is produced by someone who has seen the building and signs for it. It screens what a circuit is likely to need so you can follow a quote, check a plan or ask a better question.

Sources and methodology

Figures dated 5 September 2026. Last reviewed August 16, 2026.

NFPA 70, National Electrical Code — Articles 210 (branch circuits), 220 (load calculations) and 422 (appliances) (National Fire Protection Association, retrieved 2026-09-05. The articles governing branch-circuit sizing, the 125% continuous-load factor, and the requirement that listed equipment be installed in accordance with its instructions.)
NEC adoption maps — which edition is enforced where (National Fire Protection Association, retrieved 2026-09-05. Adoption and amendment of the National Electrical Code is local. A state or city may be on an older edition, may amend it, and may add rules of its own. Confirm the adopted edition and the amendments with the authority having jurisdiction before relying on any code figure here.)

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