What is a good mi/kWh for an EV?

For a typical sedan, anything around 3.7 to 4 mi/kWh is very good, while crossovers land closer to 3 to 3.5 and trucks near 2. What counts as good depends on the body style, since a heavy truck will never match an aerodynamic sedan. The higher your number, the less each mile costs to drive.

Does a bigger battery make an EV cheaper to drive per mile?

No. A bigger battery gives you more range because it stores more energy, but it does not change your cost per mile. That cost depends on efficiency (mi/kWh) and your electricity price, not on how large the pack is. Two cars with the same mi/kWh cost the same per mile even if one has a much bigger battery.

How do I calculate my EV cost per mile from mi/kWh?

Divide your electricity price per kWh by your car's mi/kWh. At the US average home rate of about $0.17/kWh, a car getting 4 mi/kWh costs roughly $0.043 per mile. Use the price you actually pay, since home charging and public fast-charging differ a lot.

Why does my EV get fewer miles per kWh in winter?

Batteries are less efficient when cold, and heating the cabin pulls real power that would otherwise move the car. Together these can drop your mi/kWh noticeably during a hard winter, so your cost per mile rises for those months. Preconditioning the car while it is still plugged in helps limit the hit.

EV Efficiency Explained: What mi/kWh Means

Miles per kWh (mi/kWh) tells you how far an EV travels on one kilowatt-hour of electricity. It is the electric equivalent of MPG: a higher number means the car goes farther on the same energy, which means it costs you less to drive. If you know your car's mi/kWh and what you pay for electricity, you can figure out your exact cost per mile with simple division. That is the whole game.

How mi/kWh works, and how it sets your cost

The formula is short. Your EV's cost per mile is the price you pay per kWh divided by the car's mi/kWh. At the US average home electricity rate of about $0.17/kWh, a car that gets 4 mi/kWh costs roughly $0.043 per mile ($0.17 ÷ 4). A thirstier truck at 2 mi/kWh costs about $0.085 per mile ($0.17 ÷ 2) at the same rate, or roughly double. Same electricity price, very different running cost, and the only thing that changed was efficiency.

Notice what is not in that formula: battery size. A big battery gives you more range because it holds more energy, but it does not make each mile cheaper. Two cars can both get 3.5 mi/kWh while one has a 60 kWh pack and the other an 85 kWh pack. The bigger-battery car drives farther between charges, but every mile costs the same because efficiency is identical. When people ask why one EV is cheaper to run than another, the answer is almost always mi/kWh, not the number on the battery spec sheet.

Typical mi/kWh figures by body style

Efficiency tracks closely with size, weight and shape. Rough real-world ballparks look like this:

Efficient sedans (~3.7–4 mi/kWh): aerodynamic cars like the Tesla Model 3 and Hyundai Ioniq 6 sit at the top. Low, slippery, and relatively light, they turn electricity into distance about as well as anything on the road.
Crossovers (~3–3.5 mi/kWh): the popular middle ground. Taller and heavier than a sedan, they give up some efficiency for space and ground clearance.
Large SUVs (~2.6–3 mi/kWh): more mass and a bigger frontal area push energy use up noticeably.
Trucks (~2 mi/kWh): heavy, boxy, and built to haul. Something like the F-150 Lightning lands near the bottom on efficiency, which is the price of the capability. A big battery keeps its range usable, but each mile still costs the most in this group.

These are approximate and your results will vary, but the pattern holds: the smaller and slipperier the car, the more miles you squeeze from every kWh, and the cheaper it is to run.

What weather, speed and tires do to your number

The mi/kWh a car earns in mild conditions is a starting point, not a guarantee. Several everyday factors move it:

Cold weather: batteries are less efficient when cold, and cabin heating draws real power. In a hard winter you can see efficiency drop meaningfully, so your cost per mile climbs for a few months. Preconditioning while plugged in helps.
Speed: aerodynamic drag rises sharply as you go faster. Steady highway driving at 75 mph uses more energy per mile than the same trip at 65, which is why some EVs actually post better efficiency in city driving than on the freeway.
Tires and wheels: bigger, wider, or more aggressive tires add rolling resistance and drag. Larger wheel options and all-terrain tires trade some mi/kWh for looks or grip.
Performance trims: a dual-motor or performance version of the same model is usually heavier and geared for acceleration, so it typically returns fewer miles per kWh than the standard version. You pay for that fun at the plug.

Driving style matters too. Smooth acceleration and letting regenerative braking do the work will beat hard launches and late braking every time.

Where you charge changes everything

Efficiency sets how many kWh you use; the price of those kWh finishes the math. Charging at home at roughly $0.17/kWh is far cheaper than public DC fast-charging, which averages around $0.48/kWh in the US. Run that same 4 mi/kWh sedan on fast-charging alone and its cost per mile jumps from about $0.043 to roughly $0.12. That is still often cheaper than gas, but it narrows the gap, and for a driver leaning on public charging it can shrink the savings a lot. If you can charge at home overnight, efficiency and a low home rate are the two levers that make an EV genuinely cheap to run. Our deeper walkthrough on EV charging cost per mile breaks this down further.

Put your own numbers in

Once you know a car's mi/kWh, comparing running costs is quick. You can compare EVs side by side, or drop your real efficiency, your electricity rate, and your annual miles into the gas-vs-EV calculator to see your actual cost per mile and where you break even against your current gas car. The honest numbers beat any sticker claim, and they are yours in about a minute.