WattThe / Homeowner / EV charging cost
What your miles cost on electrons: home charging at your state's rate, fast charging on the road, and the gasoline comparison side by side.
EV economics come down to one conversion: efficiency in kWh per 100 miles times your electricity price. A typical crossover at 30 kWh/100mi charged at home for 17¢/kWh costs about 5.1¢ per mile — versus roughly 14.7¢ per mile for a 30 mpg gas car at $4.40 a gallon. The gap is the reason home charging dominates the value proposition.
Public DC fast charging changes the arithmetic sharply: at 40–60¢/kWh, a fast-charged mile can cost as much as a gasoline mile. That's not a flaw so much as a pricing reality — you're paying for speed and infrastructure — but it means the share of your charging done on the road is the swing variable in annual cost, which is why this calculator blends the two explicitly.
Two refinements worth knowing: charging isn't lossless (expect 8–12% overhead between the wall and the battery, slightly worse on slow Level 1), and many utilities offer EV time-of-use rates with overnight prices far below the state average — in TOU territory, scheduling your charger is free money.
Multiply your battery's usable kWh by your rate: a 75 kWh charge at the U.S. average of about 17¢/kWh costs roughly $12.75 — typically 200–280 miles of range. Overnight EV rates can cut that substantially.
It can approach gasoline cost per mile. At 50¢/kWh, an EV using 30 kWh/100mi pays 15¢ per mile — about what a 30 mpg car pays at $4.50/gallon. Fast charging is best treated as a road-trip convenience, not a routine.
It is the EV equivalent of fuel consumption: how much energy the car uses to travel 100 miles. Efficient sedans run 24–28, crossovers about 28–34, and large trucks 45–55.
Estimates are for planning and education, not engineering design or financial advice. Verify rates with your utility and confirm electrical work with a licensed engineer or electrician.
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