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Plug & Pylon

The lookup table

What size breaker and wire does an EV charger need?

One rule, one table, and the arithmetic shown so you can check every row. Bookmark this one.

By Sawyer V. · Published September 8, 2026

An open residential electrical panel showing double-pole circuit breakers

How this page is funded: we earn a commission if you buy through our Amazon links, at no extra cost to you. It does not change what we recommend, and we say plainly when the honest answer is to buy nothing. Full disclosure.

An EV charger runs at its full rated current for hours at a stretch. The electrical code calls that a continuous load, and requires the branch circuit to be rated at not less than 125% of it. That single rule generates every number below.

The table

Breaker and typical copper conductor by charger amperage
ChargerPower at 240 VBreakerTypical copper conductorMiles/hr
16 A3.8 kW20 A12 AWGabout 13
24 A5.8 kW30 A10 AWGabout 20
32 A7.7 kW40 A8 AWGabout 27
40 A9.6 kW50 A6 AWGabout 34
48 A11.5 kW60 A6 AWGabout 40
50 A12.0 kW70 A4 AWGabout 42
64 A15.4 kW80 A3 AWGabout 54
Conductor sizes are typical values for copper at the 75 C terminal rating and are orientation only. Actual sizing depends on run length and voltage drop, insulation type, ambient temperature, conduit fill and the terminal ratings of your specific breaker and charger. Miles per hour assume 3.5 mi/kWh. Your electrician sizes the conductors; your inspector approves them.

The arithmetic, row by row

How the breaker column is produced

48 A charger: 48 x 1.25 = 60 A. 60 is a standard size, so the breaker is 60 A.

40 A charger: 40 x 1.25 = 50 A. Standard size, so 50 A.

32 A charger: 32 x 1.25 = 40 A. Standard size, so 40 A.

50 A charger: 50 x 1.25 = 62.5 A. Not a standard size, so round up to 70 A.

Standard breaker sizes go 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100.

That last row is worth pausing on, because it catches people out: a charger set to 50 amps needs a 70-amp circuit, not a 60-amp one. It is also why 48 amps is the most common top-end setting on home chargers -- it is the highest figure that lands neatly on a 60-amp breaker.

Working the other way: what your panel can support

More usefully, you often know your breaker and want to know the charger. Divide by 1.25, or multiply by 0.8:

Maximum charger amperage by available circuit
Circuit availableMaximum continuous charger drawPower
20 A16 A3.8 kW
30 A24 A5.8 kW
40 A32 A7.7 kW
50 A40 A9.6 kW
60 A48 A11.5 kW
70 A56 A13.4 kW

Aluminum conductors

Aluminum has lower ampacity than copper for the same size, so an aluminum feed needs a larger conductor -- and it needs terminals and antioxidant treatment rated for aluminum. It is common and perfectly acceptable on longer runs where it is meaningfully cheaper. Ask your electrician which they are quoting, because it affects the price comparison between bids.

Choosing a charger to fit your panel

If your panel can spare 60 amps, a 48-amp charger fits. If it can spare 50, a 40-amp charger fits and costs less to wire. If you genuinely do not know, buy an adjustable unit and set it to whatever the electrician confirms.

One charger per circuit size

Ranked for a first home charger. Every row jumps to the full write-up below.

#ProductBest forMax outputPrice
1Grizzl-E ClassicHarsh weather and no app. J1772, 24 ft cable.Harsh weather and no app40 A9.6 kWCheck price on Amazon#ad how we are funded
2Emporia Level 2 EV Charger (Classic)A first charger, hardwired. J1772, 24 ft cable.A first charger, hardwired48 A11.5 kWCheck price on Amazon#ad how we are funded
3ChargePoint Home FlexHomes with an uncertain panel. J1772, 23 ft cable.Homes with an uncertain panel50 A12 kWCheck price on Amazon#ad how we are funded

The three units in detail

A 40 A unit for a 50 A circuit, a 48 A unit for a 60 A circuit, and an adjustable unit for when you do not know yet.

1. Harsh weather and no app

Grizzl-E Classic

United Chargers · J1772 · 40 A / 9.6 kW · 24 ft cable

A cast-aluminum box with no app, no account and no firmware to update. If you want a charger that behaves like an appliance, this is the one.

What is good

  • Cast aluminum NEMA 4 / IP67 enclosure, built for outdoor mounting
  • No app, no account, no network dependency
  • Amperage is set with physical switches, not software
  • Protections for over-current, over-voltage, ground fault and over-temperature

What is not

  • 40 A ceiling, slower than the 48 A units if your panel can take more
  • No scheduling, so off-peak charging has to be set in the car
  • The cold-flexible 24 ft cable is only on the Extreme Edition
Published specifications for the Grizzl-E Classic
Maximum output40 A / 9.6 kW at 240 V
Adjustable16, 24, 32 or 40 A
ConnectorSAE J1772
Cable24 ft on the Extreme Edition
EnclosureCast aluminum, NEMA 4 / IP67
CertificationUL certified
Warranty3 years

Skip this if: Skip it if you want scheduled charging or energy tracking in an app. The Classic deliberately has neither.

Specifications above are the manufacturer’s published figures. Source: United Chargers, InsideEVs. We have not tested this unit — see how we pick.

Check price on Amazon#ad how we are funded

2. A first charger, hardwired

Emporia Level 2 EV Charger (Classic)

Emporia · J1772 · 48 A / 11.5 kW · 24 ft cable

The safe default for a first home charger: 48 amps hardwired, a genuinely long cable, a NEMA 4 outdoor-rated case, and no subscription attached to the app.

What is good

  • 48 A hardwired is the fastest tier most homes can realistically support
  • 24 ft of cable reaches across a two-car garage without a fight
  • NEMA Type 4 enclosure is rated for outdoor mounting
  • Energy monitoring in the app with no subscription

What is not

  • Drops to 40 A if you use the NEMA 14-50 plug rather than hardwiring
  • The app is the only way to change the amperage setting
Published specifications for the Emporia Level 2 EV Charger (Classic)
Maximum output48 A / 11.5 kW at 240 V (hardwired)
Plug-in output40 A with the NEMA 14-50 plug
ConnectorSAE J1772
Cable24 ft
EnclosureNEMA Type 4, indoor or outdoor
CertificationUL listed, Energy Star
Warranty3 years

Skip this if: Skip it if you want a unit with no app or network connection at all. The Grizzl-E Classic is the simpler machine.

Specifications above are the manufacturer’s published figures. Source: Emporia Energy. We have not tested this unit — see how we pick.

Check price on Amazon#ad how we are funded

3. Homes with an uncertain panel

ChargePoint Home Flex

ChargePoint · J1772 · 50 A / 12 kW · 23 ft cable

The most adjustable unit here. It can be set anywhere from 16 A to 50 A, which makes it the one to buy when you do not yet know what your panel will allow.

What is good

  • Six selectable amperage settings from 16 A to 50 A
  • Sold in both hardwired and NEMA 14-50 versions
  • Rated for indoor or outdoor installation
  • The app is mature and does not require a subscription

What is not

  • 23 ft is a foot shorter than the longest cables in this group
  • The 50 A setting needs a bigger circuit than most panels have spare
Published specifications for the ChargePoint Home Flex
Maximum output50 A / 12 kW at 240 V
Amperage settings16, 24, 32, 40, 48 or 50 A
ConnectorSAE J1772
Cable23 ft
InstallationHardwired or NEMA 14-50
CertificationUL listed, Energy Star
Warranty3 years

Skip this if: Skip it if your circuit is already fixed and you just want the cheapest safe 40 A unit. You are paying for flexibility you will not use.

Specifications above are the manufacturer’s published figures. Source: ChargePoint, ChargePoint. We have not tested this unit — see how we pick.

Check price on Amazon#ad how we are funded

FAQ

Questions people actually ask

What size breaker do I need for a 48-amp EV charger?
A 60-amp double-pole breaker. The continuous-load rule sizes the circuit at 125% of the charger's draw: 48 x 1.25 = 60.
What size wire for a 50-amp EV charger circuit?
A 50-amp circuit is typically 6 AWG copper at the 75 C terminal rating, but the actual size depends on run length, insulation type, ambient temperature and conduit fill. Your electrician sizes it.
Why does a 50-amp charger need a 70-amp breaker?
Because 50 x 1.25 = 62.5, which is not a standard breaker size, so it rounds up to 70. This is why 48 amps is the most common top setting -- it lands neatly on a 60-amp breaker.
Can I put an EV charger on a 30-amp circuit?
Yes, limited to 24 amps continuous, which is 5.8 kW or roughly 20 miles of range per hour. Many chargers can be set down to that level.
Is aluminum wire acceptable for an EV charger circuit?
Yes, with the correct larger conductor size and terminals rated for aluminum. It is common on longer runs because it costs less.

Sources

Where these numbers come from

  1. NEC Article 625: EV charging equipment — WireRefArticle 625 continuous-load requirement for EV supply equipment.
  2. NEC 125% rule for EV charger breaker and wire sizing — Electric Vehicle GeekPublished sizing ladder corroborating the breaker column. Fetched 2026-09-08.
  3. How to size an EV charger circuit, NEC 220.57 and Article 625 — TestTalk HQCorroborating published sizing method. Fetched 2026-09-08.

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