Every home charging cost question comes down to two numbers: how many kilowatt-hours (kWh) your EV actually uses, and what you pay per kWh. Once you have those, the math is one multiplication. Here is how to get both numbers right - including the charging losses most calculators quietly skip.
kWh per mile: the EV equivalent of MPG
Most modern EVs use between 0.25 and 0.35 kWh per mile (or 3-4 miles per kWh, the figure on the EPA sticker). Where a car lands depends on size, speed and weather:
| Vehicle type | Typical efficiency | kWh per 100 miles |
|---|---|---|
| Efficient sedan (Ioniq 6, Model 3) | 3.6-4.2 mi/kWh | 24-28 kWh |
| Compact SUV (Model Y, ID.4, EV6) | 3.0-3.5 mi/kWh | 29-33 kWh |
| Large SUV / pickup (F-150 Lightning, R1S) | 2.0-2.5 mi/kWh | 40-50 kWh |
Highway driving at 75+ mph, cold weather and roof boxes all push consumption up - winter can add 20-30%. Your car's trip computer shows your real lifetime figure; use that, not the sticker.
How many kWh is a "full charge"?
Battery sizes in 2026 run from about 40 kWh (small city EVs) to 100+ kWh (long-range and trucks). But you rarely charge from empty to full. Day to day, most drivers replace what they drove:
Don't forget charging losses
The energy that leaves your wall is more than the energy that lands in the battery. Level 2 home charging is typically 88-92% efficient; Level 1 (regular outlet) is worse, around 75-85%, because the car's systems stay awake longer. When you estimate cost from kWh used, divide by 0.9 to get what you actually pay for. More on the Level 1 penalty in charging from a regular outlet.
Turning kWh into dollars
The formula: monthly miles / efficiency x 1.1 (losses) x your rate per kWh. What that looks like at common US residential rates:
| Rate | 1,000 miles/month (3.2 mi/kWh car) | Per mile |
|---|---|---|
| Off-peak $0.08/kWh | ~$27.50 | 2.8 cents |
| Average $0.16/kWh | ~$55 | 5.5 cents |
| High-cost $0.30/kWh | ~$103 | 10.3 cents |
For comparison, a 30 MPG gas car at $3.50/gallon costs about 11.7 cents per mile - which is why the rate you charge on matters more than the car you drive. See EV vs gas fuel cost for the full comparison, and home charging cost per month for more scenarios.
Find your real rate
The number on your bill is not one number - supply, delivery, taxes and time-of-use windows all stack. Your effective overnight rate is what counts for EV charging. How to read your power bill walks through finding it, and are time-of-use EV plans worth it covers when switching pays.
What to read next
- Home charging cost per month - worked monthly budgets.
- 7 ways to cut your charging bill - rate, timing and hardware.
- How long does home charging take - the time side of the same math.
- Costs & Savings section - every cost guide.
Sources: EPA fueleconomy.gov efficiency ratings, DOE/AFDC charging-efficiency guidance, and published utility residential rates, November 2026. Your car's displayed efficiency and your utility's current tariff are the authoritative figures for your own math.