How Many Amps Does an EV Charger Use?

Home EV chargers draw between 12 and 80 amps, and in practice almost everyone buys 40 or 48. But that is not really what you asked, because three different numbers get called “the amps” and mixing them up is how people end up buying a charger their panel cannot feed. Let us separate them first, because once they are separate the rest of this is one line of arithmetic.

One: the rated amperage.The number on the box — 40 A, 48 A. It is the maximum current the charger is built to deliver.

Two: the actual draw. What it pulls right now, which is its configured amperage, not necessarily its rated one. A 48-amp charger set to 24 amps draws 24. And unlike almost everything else in your house, it draws that figure continuously for hours.

Three: the circuit rating. What the breaker and the wire have to be, which is always larger than the draw. This is the number people get wrong, and the gap between two and three is not optional.

The one rule that connects them

EV charging is a continuous load. Electrical code sizes a continuous load’s branch circuit to 125% of the draw— which the industry says backwards as the “80% rule”, meaning a circuit may carry 80% of its rating continuously. Both phrasings are the same arithmetic:

Charger draw × 1.25 = circuit size. Or: circuit size × 0.8 = maximum charger draw.

So a 40-amp charger needs a 50-amp circuit. A 48-amp charger needs 60. An 80-amp charger needs 100. And running it the other way, a 30-amp circuit supports a 24-amp charger, and a 20-amp circuit supports 16.

The reason is heat rather than bureaucracy. A conductor carrying 40 amps for a dryer’s forty minutes behaves very differently from the same conductor carrying 40 amps for ten hours straight. The derating gives the wire, the terminations and the breaker margin to shed heat they would otherwise accumulate. It is the same physics that makes extension cords a bad idea for charging.

One row in that table deserves a note, because it is the exception we keep flagging. Autel states that its 50-amp MaxiCharger needs a 70-amp circuit for full output. That is more than the 125% rule implies, it comes from Autel’s own page, and we publish it rather than rounding it down to the 60 amps readers expect. If you are planning around that unit, plan around 70.

Converting amps into something you can use

Amps on their own tell you about your wiring. To learn about your car you need two more conversions, and both are one multiplication. These are our calculations with the assumptions printed, not figures off a box.

Amps to kilowatts:amps × 240 volts ÷ 1000. So 40 amps is 9.6 kW; 48 amps is 11.5 kW; 24 amps is 5.8 kW.

Kilowatts to miles per hour:kW × your car’s miles per kWh. We use a reference 3.5 miles per kWh throughout this site, which is a reasonable mid-range EV in mild weather. So 9.6 kW is about 34 miles of range per hour. A heavy truck in winter might manage 2.0 and a small efficient sedan 4.5, which moves that figure a long way in both directions — our winter charging page has the cold-weather side.

Now the sanity check that makes most amperage anxiety evaporate. The average US driver covers well under 40 miles a day. At 40 amps that is a bit over an hour of charging. At 24 amps it is two. Your car is parked for ten or twelve. Unless you drive unusually far or have an unusually short charging window, you are choosing between “finished by midnight” and “finished by 1am”, and both happen while you are asleep. We work this through properly in what size charger do I need.

The ceiling that makes all of this moot

Here is the part charger listings have no incentive to tell you: the amperage that matters is the lower of what your charger delivers and what your car accepts. And it is usually the car.

Every EV has an onboard charger— the hardware inside the vehicle that converts the AC coming up the cable into DC for the battery. Its rating is a hard ceiling. 11.5 kW is a common figure; plenty of vehicles stop at 7.7 or 11; only a handful accept 19.2. Feed an 11 kW car from an 80-amp charger and you get 11 kW, on a 100-amp circuit you paid a great deal of money for.

We have written six per-vehicle guides and the pattern is consistent. Toyota publishes “11-kW onboard charger” for the bZ. Kia publishes 10.9 kW on every EV6 and EV9 trim. Volkswagen publishes an 11 kW maximum AC acceptance rate for the ID.4. The Cadillac LYRIQ is the rare case where some trims take 19.2 kW. And Hyundai publishes no figure at all for the IONIQ 5— which is why that page derives the ceiling from Hyundai’s own charge times and shows the working.

So the honest shopping order is: find your car’s AC acceptance rate first, then buy a charger that meets or modestly exceeds it, then size the circuit to the charger. Doing it in the other order is how people end up on our fastest-chargers roundup buying 80 amps for a car that will politely decline most of it.

Why adjustable amperage is the feature to want

Given all of the above, the most valuable thing a charger can do about amperage is let you change it. A unit you can configure fits the circuit you have today and the circuit you might have later, and it is the difference between a charger that survives a move and one that does not.

Two things to note about that table. The mechanism differs: ChargePoint and Autel set current in software, while Grizzl-E and ELEGRP use a physical switch, which means a circuit change is a service visit rather than a tap. And the absences matter: several hardwired units we rate highly — the EVIQO 48A, the Lectron Nexus 48A, the Emporia Pro — publish no adjustable range, so we treat their rated amperage as the configuration you are buying rather than assuming a lower setting exists.

Whatever you buy, get the configured amperage written on the invoice. On the DIP-switch units the setting ends up sealed inside the enclosure where you will never see it again, and a wrong setting is a common cause of a charger that will not charge or a breaker that keeps tripping.

Quick picks

Ranked on published specs, charging speed, electrical fit and value. Select a row to jump to the full write-up. We have not bench-tested these chargers — here is exactly what we do instead.

#	Product	Best for	Price
1	ChargePoint Home Flex The safest default for most homes: you set the amperage in the app to 16, 24, 32, 40, 48 or 50A, so one charger fits whatever circuit your panel can spare today and scales up if you upgrade later. The app is the most mature here, firmware arrives over the air, and the warranty is long.	Widest app-set range, 16-50 A	$516.71 · View on Amazon Price as of October 18, 2026. #ad How we’re funded
2	Autel MaxiCharger 80A The ceiling of home AC charging: 19.2 kW on a 100-amp circuit, which is roughly double what a 48-amp charger does. Almost no car can actually take it — most cap their onboard charger somewhere between 7.7 and 11.5 kW — so buy this for a specific vehicle that accepts 80 amps, or for a future-proofed circuit you already have. Otherwise it is a very good, very expensive 48-amp charger.	6-80 A, the widest we track	$908.65 · View on Amazon $1,299.0030% off Price as of October 18, 2026. #ad How we’re funded
3	Grizzl-E Classic Connect 40A Grizzl-E's cast-aluminum build with a WiFi radio in it. You get the IP67 body and the cold-flexible 25 ft cable that made the brand's name, plus scheduling, usage history and utility demand-response programs in the Grizzl-E Connect app — in a plug-in unit that comes off the wall when you move. The amperage is still set with a DIP switch, which is either charmingly honest or annoyingly analog depending on your taste.	DIP switch, nothing to log into	$349.99 · View on Amazon Price as of October 18, 2026. #ad How we’re funded
4	ELEGRP 40A Portable Level 2 Charger The full-speed portable. A genuine 40 amps on a NEMA 14-50, an IP67 station body rated -22F to 122F, and a 25-foot cable - the longest here by five feet - for less than the 32A unit costs. It is the heaviest thing here to coil and there is no app, but if the portable is also going to be your everyday charger, this is the one that does not make you choose.	Five settings at the lowest price	$209.99 · View on Amazon Price as of October 18, 2026. #ad How we’re funded

Once you have settled the amps, the number worth your attention is what those kilowatt-hours cost. Our cost-to-charge calculator takes your own rate, and time-of-use chargingis where the savings actually live — a slower charger on a cheap overnight rate beats a fast one at peak every single night.