How Much Does It Cost to Charge an EV? Home vs Public, Per Mile

An EV never gets filled the way a gas tank does, but the cost question has an exact answer, and it is smaller than most people guess. Three inputs decide it: how big the battery is, how much of it you are refilling, and what you pay per kilowatt-hour. Run the typical case — a 75 kWh battery charged from 20% to 80% at the 2026 US residential average of about $0.175/kWh — and the charge costs $8.75. Not per hour. Total. That single number, and how to recompute it for your car and your rate, is what this guide is about.

People get this wrong in three predictable ways. They price a full 0–100% charge that nobody actually performs day to day, which inflates the answer by two-thirds. They forget charging losses, so the math never matches the bill: the meter records 50 kWh while only 45 land in the pack, and you pay for all 50. Or they take a number worked out at a home rate and assume a public fast charger lives in the same universe. It does not. Per kilowatt-hour, public charging typically runs two to four times what you pay at home, and some networks do not bill per kilowatt-hour at all.

The quick answer

For a 20–80% charge at the US home average of $0.175/kWh, with the standard 90% charging efficiency:

Three things to notice before you take a number from that table. First, everything scales linearly with the rate. If you pay $0.10/kWh overnight, the 75 kWh charge drops to $5.00; at $0.25 it is $12.50; at a public station charging $0.35 it doubles to $17.50. Second, it scales linearly with battery size too, so interpolating is safe: a 55 kWh pack lands proportionally between the 40 and 60 rows, no separate lookup needed. Third, the "full charge" column is a reference, not a routine. Daily charging happens in the middle of the pack, so the left column is the number that describes your actual life with the car. More on why in a moment.

The formula the calculator runs

The EV charging cost calculator runs three lines, in this order:

• energy to battery = battery kWh × (to% − from%)
• grid energy = energy to battery ÷ efficiency
• cost = grid energy × rate

The first line is intuitive: refilling 60% of a 75 kWh pack means 45 kWh of energy has to end up in the battery. The third line is how every electric bill works — energy times rate. It is the middle line that trips people, because it says you must buy more energy than you keep. Charging is not lossless. Some of what comes out of the wall becomes heat in the cable, the onboard charger, and the pack itself, and some is spent converting AC from the grid into the DC the battery stores. On Level 2 home charging that overhead typically eats 10–15% of what you draw, which is why the calculator's efficiency setting defaults to 90% and accepts anything from 80% to 95% under Advanced.

Four inputs, then: battery capacity in kWh (use the usable figure if the manufacturer quotes both usable and gross), the state-of-charge window you are charging across, your rate in dollars per kWh, and the efficiency. The calculator accepts batteries from 10 to 200 kWh, which covers everything from a plug-in city car to the largest electric trucks.

Worked example: the default charge, line by line

Take the defaults and grind through them by hand once, because after this the calculator is just saving you the arithmetic.

A 75 kWh battery, charged from 20% to 80%, at $0.175/kWh, with 90% efficiency:

1. Charge window: 80% − 20% = 60%, or 0.60 of the pack.
2. Energy to battery: 75 × 0.60 = 45 kWh. That is what the car gains.
3. Grid energy: 45 ÷ 0.90 = 50 kWh. That is what your meter records, because the 10% overhead has to come from somewhere.
4. Cost: 50 × $0.175 = $8.75.

The full-charge reference comes from the same machinery with the window set to 100%: (75 ÷ 0.90) × $0.175 = 83.3 kWh billed, or $14.58. Worth knowing, rarely paid, because you almost never arrive home at 0% and you should not routinely charge to 100%.

Notice what did not appear anywhere in that calculation: charging speed. A Level 2 home unit and a slower plug deliver the same kilowatt-hours at the same rate; one just takes longer. At home, time is free while you sleep. Speed only becomes money at public stations that bill by the minute — a pricing model we will get to.

It is also worth scaling this once to a year, because the per-charge figure is deceptively small. Suppose your driving pattern works out to that 20–80% charge twice a week. That is 104 charges × $8.75 = about $910 a year to fuel the car at home rates. Keep that figure in mind: it is the anchor that every public-charging premium and every rate change gets measured against, and it is the number that should sit next to a year of gas receipts when you compare.

Charging losses: why you pay for more than the battery holds

The gap between line 2 and line 3 above deserves its own section, because it is the part of the math that quietly breaks people's mental model. You added 45 kWh to the battery, but you bought 50 kWh. The missing 5 kWh became heat during AC-to-DC conversion and charging. At $0.175/kWh, that is about $0.88 of electricity per charge that never reaches the pack. On the twice-a-week pattern from the last section, the overhead alone runs roughly $91 of that $910 annual bill — a clean 10% of everything you spend on charging, paid for energy you never got to drive on.

The efficiency setting is the lever here, and the calculator bounds it realistically at 80–95%. For the same 45 kWh into the pack:

• At 80% efficiency you draw 56.25 kWh, and the charge costs $9.84.
• At the 90% default you draw 50 kWh: $8.75.
• At 95% you draw 47.4 kWh: $8.29.

A fifteen-point swing in efficiency moves this charge by about a dollar and a half. That is worth getting right if you are computing annual costs, and it is why the setting lives under Advanced rather than being buried in the formula. One nuance from the other direction: DC fast charging is actually more efficient at the car, because the conversion to DC happens in the station's hardware instead of your onboard charger. But fast-charging networks price their electricity so much higher per kWh that the efficiency gain never wins. The rate dominates; it always dominates.

Home vs public: the two-to-four-times problem

Everything so far assumed the cheap case: charging at home on a residential rate. That assumption is the single biggest variable in what an EV costs to run, bigger than battery size, bigger than efficiency. Public Level 2 stations and especially DC fast chargers typically charge two to four times the residential rate per kilowatt-hour.

The arithmetic does not change at all. Energy times rate is energy times rate. To price a public session, open the calculator and replace your home rate with the station's advertised rate; nothing else needs to move. What changes is the answer:

Same car, same 45 kWh added, three different bills: $8.75 at home, around $17.50 at a public station running about twice the home rate, up to $35.00 at a fast charger near four times it. The convenience is real — a fast charger does in a lunch stop what your garage does overnight — but you are paying a steep premium per unit of energy for that speed.

That premium is why the split of your charging matters more than any single session. A driver who plugs in at home every night and fast-charges only on holiday trips pays close to the home rate for almost every mile. A driver without home charging, living off public stations, pays the multiplied rate for all of them, and their annual cost can look like a different vehicle's entirely. If you are deciding whether an EV pencils out for you, this is the question to answer first: where will most of the kilowatt-hours actually come from?

Put numbers on the split and the stakes get concrete. The twice-a-week pattern from earlier — 104 of the default charges a year — costs about $910 done entirely at home. Move the same year of charging to a public station at twice the home rate and it runs $1,820; live on DC fast charging at four times home and it is $3,640. A realistic mixed year — say 90 charges at home plus 14 sessions at the $22.50 interstate price worked through below — lands near $1,100: 90 × $8.75 = $787.50, plus 14 × $22.50 = $315. The formula never changed once across those four scenarios. Where the kilowatt-hours come from moves the annual bill by up to a factor of four, and no other input in the calculator comes close to that leverage.

And watch the price unit. Some networks bill per minute rather than per kWh. Per-minute billing means the cost of your session depends on how fast your particular car can accept charge: a vehicle that fast-charges slowly pays more for the same energy than one that charges quickly, at the same station, on the same afternoon. Before you plug in, check whether the posted price is per kWh or per minute, because the calculator's math assumes you are buying energy, not time.

Two more worked examples

The default charge is the road-trip-scale case. Here are the two other sessions that make up real EV life, with the arithmetic shown.

The nightly top-up. A 60 kWh compact gets driven to work and back and arrives home at 60%. You plug in and charge to 80% overnight at $0.175/kWh:

1. Window: 80% − 60% = 20%, so 60 × 0.20 = 12 kWh into the battery.
2. Grid energy: 12 ÷ 0.90 = 13.3 kWh billed.
3. Cost: 13.3 × $0.175 = $2.33.

Call it two dollars and change per night. Thirty nights of that habit is $70.00 a month of charging, and that is the honest monthly fuel bill for a commuter doing this pattern — not the scarier numbers you get by multiplying full charges nobody performs. If you want to see what that does to the rest of your bill, the electricity usage calculator puts EV charging alongside your other loads.

The fast-charge session. Same 75 kWh car from the default example, but you are on the interstate and the fast charger posts $0.45/kWh, comfortably inside the two-to-four-times band. Charging 20–80%:

1. Energy to battery: 75 × 0.60 = 45 kWh.
2. Grid-side energy: 45 ÷ 0.90 = 50 kWh (in practice fast charging wastes a bit less in the car, so nudge the Advanced efficiency up toward 95% if you want precision).
3. Cost: 50 × $0.45 = $22.50.

That is 2.6 times the identical charge at home. Not a rip-off, exactly — you bought a couple hundred miles of range in a single stop — but it reframes fast charging as what it is: the expensive convenience option, not the default fueling plan.

The 20–80% window, and when to break it

The calculator defaults to a 20–80% window because that is how EVs actually get used, not because it makes the numbers prettier. Daily charging happens in the middle of the pack for two reasons, one practical and one chemical.

Practically, the last stretch to 100% is slow. Charging speed tapers hard as the pack fills, so the final 20% takes disproportionately long — fine overnight, painful at a paid station, and doubly painful at one billing by the minute. Chemically, lithium cells dislike the extremes. Regularly holding the pack at 100%, or draining it toward empty, stresses the cells in a way the middle band does not. Living at 20–80% keeps the battery healthy; running to empty is also simply impractical, since nobody plans to coast into the driveway at 0%.

So treat the window as an input that reflects intent. For the daily cycle, 20–80% is the honest default and $8.75 is the honest cost. Widen it the night before a long trip, when you genuinely need the range, and run the machinery once more for that morning. Charging 20–100% is an 80-point window:

1. Energy to battery: 75 × 0.80 = 60 kWh.
2. Grid energy: 60 ÷ 0.90 = 66.7 kWh billed.
3. Cost: 66.7 × $0.175 = $11.67.

The full range costs $2.92 more than the daily charge — paying that a handful of times a year for road trips is exactly what the top of the battery is for. Note that this is cheaper than the $14.58 full-charge reference, because that figure prices the theoretical 0–100% fill; starting from 20%, as you actually would, the trip-eve premium is smaller still.

Cost per mile: the number that beats gas

Dollars per charge is what the calculator returns, but dollars per mile is what settles arguments, because it is the only unit a gas car can be compared in. The conversion is one division:

cost per mile = charge cost ÷ miles added

A 75 kWh battery charged 20–80% adds a couple hundred miles of range in an efficient EV. Call it 200 miles: $8.75 ÷ 200 = about 4.4 cents per mile at home rates. Even at the calculator's efficiency floor, the answer stays under a nickel a mile. Public charging scales that linearly with the rate — the same miles cost roughly 9 cents each at twice the home rate and around 17–18 cents at four times it.

Gasoline, for the same miles in a comparable car, costs far more; the gap is wide enough that the comparison survives any reasonable set of assumptions about your specific car. The pattern that emerges is worth stating plainly: an EV charged at home is dramatically cheaper per mile than gas, an EV charged mostly on DC fast chargers narrows that gap considerably, and where your charging actually happens is therefore the biggest financial fact about owning one. Run your own windows and rates through the calculator and do the division for your car's real-world range — it is a two-minute exercise that replaces every generic claim in every direction.

Getting your rate right

The rate is the input people are most cavalier about, and it is the one doing the most work. The $0.175/kWh used throughout this guide is the US residential average as of 2026, and averages are exactly what you should not use, because residential rates vary widely by state and plan. The right number is on your own electricity bill, and it is usually not presented as one tidy figure — supply and delivery charges are billed as separate per-kWh line items that have to be added together.

Two honest ways to get it: sum every per-kWh line item on the bill, or divide a month's total bill by the month's kWh. The cost per kWh calculator does the second method for you, and our guide to how much electricity costs walks the anatomy of the bill in detail. One more wrinkle worth checking: if your utility prices electricity differently by time of day, use the rate for the hours you actually charge. EVs mostly charge overnight, and if your overnight rate is lower than your headline rate, your real charging cost is lower than the average-rate estimate — checking this detail is usually good news for the overnight charger.

Once you know your true rate, it is reusable everywhere: the same number prices your other appliances, your heating, and every kilowatt-hour decision in the house. The EV is just the biggest new line item most households ever add.

Common mistakes

• Quoting the full-charge cost as the daily cost. A 0–100% charge on the default setup is $14.58; the 20–80% charge you actually perform is $8.75. Using the wrong one overstates your fuel budget by two-thirds.
• Ignoring charging losses. Multiplying battery kWh by your rate skips the ÷ 0.90 step and understates every charge by about 10%. The meter bills grid energy, not battery energy.
• Using the national average instead of your bill. $0.175 is a placeholder. Your real rate — supply plus delivery, for the hours you charge — can sit well above or below it, and every result scales with it.
• Applying home math to public sessions. The formula transfers; the rate does not. Swap in the station's rate or your estimate will be off by a factor of two to four.
• Pricing a per-minute station by kWh. If the network bills by time, your car's charging speed sets the cost, and the posted per-minute figure needs your car's actual acceptance rate to translate into dollars.
• Entering gross pack size when the spec sheet quotes usable. The calculator wants usable capacity. If the manufacturer lists both, the usable figure is the one your charge windows apply to.

The whole calculation in one paragraph

Multiply the battery's usable kWh by the fraction of it you are refilling, divide by the charging efficiency (90% is right for home Level 2 unless you know better), multiply by the rate from your own bill, and read the answer in dollars: $8.75 for the standard 75 kWh, 20–80%, $0.175 case. Swap in a station's rate to price a public session, expect two to four times home, and keep daily charging in the 20–80% band with full charges saved for trip mornings. Divide any of it by the miles gained and you have the per-mile figure that makes the gas comparison unnecessary to argue about.