Amperage opens every Level 2 charger's spec sheet, so buying the largest number your budget permits is a tempting shortcut, but it gets things backwards. The right amperage is whatever makes up your real daily mileage within your real overnight window. Anything beyond that costs more and requires a larger circuit for speed you will seldom use.
The formula
| Amperage | Power | Range added per hour | Daily miles covered in 8 hours |
|---|---|---|---|
| 16A | 3.8 kW | ~8-10 miles | ~65-80 miles |
| 24A | 5.8 kW | ~12-16 miles | ~95-130 miles |
| 32A | 7.7 kW | ~20-25 miles | ~160-200 miles |
| 40A | 9.6 kW | ~25-32 miles | ~200-255 miles |
| 48A | 11.5 kW | ~30-38 miles | ~240-305 miles |
Here is the calculation: divide daily miles by the miles-per-hour at that amperage to get the hours needed to fully replace a day's driving. When the result sits well within your overnight window, usually 8-10 hours, extra amperage is unnecessary, even if a higher-rated charger is on the shelf beside it.
Worked examples by driver
Average commuter (37 miles/day, national average)
Federal travel data puts the U.S. average at 37 miles a day. A 32A charger restores that in under 2 hours, which leaves 6-8 hours of buffer for a longer day or a missed charge.
For a commute near or at the national average, 40A or 48A hardware and the bigger circuit it demands are hard to justify.
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Long commuter or two-EV household (60+ miles/day)
Covering a 60-mile round trip takes roughly 2-3 hours at 40A. That still fits an overnight window easily, but the margin tightens quickly if another EV uses the same charger.
Households with two EVs should size for whichever car needs more, or choose a power-sharing unit; our best dual EV charger picks list units designed for this.
Why more amps isn’t automatically better
Once amperage exceeds what your car's onboard charger can accept, it adds nothing. Numerous EVs, among them most plug-in hybrids and several base-trim electric models, limit their onboard chargers to 32-40A whatever the wall unit offers. Our 40A vs. 48A comparison shows which vehicles can use the upper end.
As a worked example of a mid-range choice, WenStorm’s Level 2 Portable is rated at 32A (7.7 kW) on a NEMA 14-50 outlet and costs $219.99, with adjustable 16A, 24A and 32A settings per its maker. That’s in the range most commuters need, per the table above, and it doesn’t go higher, so a driver with a very long commute or a large onboard charger may want 40A or more. A 16A Level 1 version at $169.99 runs on a standard 120V outlet.
A bigger circuit comes with higher amperage. The National Electrical Code's 80% continuous-load rule requires a charger's breaker to be rated 25% above its output, so going from 32A to 40A can decide whether you reuse an existing 50A circuit or pay an electrician to install a new one, as our installation cost guide details.
The bottom line
Pick a charger that suits your daily miles and overnight window instead of the largest figure on the packaging. Most drivers do fine at 32A, and only long commutes, two-EV households, or a wish for a quick full charge make 40A or 48A, along with the bigger circuit, worth paying for. Our best Level 2 EV charger picks rank the leading units in every amperage class.
Last updated August 4, 2026: re-verified the Federal Highway Administration’s 37-mile national daily-driving average and the amperage-to-miles-per-hour figures against current NHTS data — no changes needed, all numbers still hold.
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Frequently Asked Questions
How can I work out which amperage of EV charger I should get?
Take your average daily miles and divide by your vehicle's charging speed at a given amperage, then confirm the answer fits your overnight charging window. The typical driver covers about 37 miles a day, the U.S. average per federal travel data, and a 32A charger at 20-25 miles per hour replaces that in under 2 hours. In other words, most households buy more amperage than their driving calls for.
Which amperage of EV charger suits an ordinary commute?
A 32A charger (7.7 kW, roughly 20-25 miles of range per hour) handles a 40-mile round-trip commute in about 2 hours, far inside an 8-10 hour overnight window. Move up to 40A only when your commute is over about 60 miles a day, two EVs share a single charger, or you want a full charge in under 6 hours and not 8-10.
Does more amperage always make an EV charger better?
No. Amperage that exceeds what your car's onboard charger accepts, or what your daily driving requires, gains you nothing. Many EVs limit their onboard chargers to 32-40A whatever the wall unit's rating, and more amperage also calls for a larger, costlier circuit under the National Electrical Code's 80% continuous-load rule. Our <a href="/guides/40-amp-vs-48-amp-ev-charger/">40A vs. 48A comparison</a> explains when the additional amps do help.
What amperage does a Tesla need to charge overnight?
On only 24-32A (about 15-25 miles per hour), a Tesla Model 3 or Y fully restores a typical daily commute overnight. The full 48A supported by a Tesla Wall Connector matters mostly for long commutes, households with two Teslas, or drivers who want to go from nearly empty to full in under 5 hours, and isn't needed for everyday use.
What is the lowest amperage worth getting for an EV charger?
The practical minimum for a dedicated Level 2 charger is 24A (5.8 kW), which adds about 12-16 miles of range per hour. That covers average daily driving overnight but leaves little margin for a longer trip or a missed night. For most buyers 32A is the better baseline, as moving from 24A to 32A seldom changes the circuit size required yet adds a real cushion.
Will a larger battery require a charger with more amps?
Not for everyday charging. Battery size influences how long a charge from empty takes and not how many amps typical partial top-ups need. A big-battery EV such as a Rivian R1S gains from higher amperage chiefly when charging from a low state of charge after a long trip, whereas for an average nightly top-up of 30-40 miles even a large-battery EV needs only enough amperage to replace those miles in the time available.