The short answer
A Level 2 charger adds your mileage times your car's efficiency times your rate, divided by about 0.9 for losses. For a typical EV driven 1,000 miles a month at 16 cents per kWh, that is roughly $50 a month — comparable to adding an electric water heater. The charger itself adds nothing when idle; the consumption is entirely the car's.
monthly kWh = (miles / 100) x kWh-per-100-miles / 0.9
Then multiply by your rate per kWh
Your kWh per 100 miles is the EPA figure for your trim, on the window sticker or at fueleconomy.gov. The 0.9 accounts for AC-to-DC conversion losses — roughly 10% of metered energy never reaches the battery.
By vehicle, at three mileages
| Vehicle (EPA trim) | kWh / 100 mi | 500 mi/mo | 1,000 mi/mo | 1,500 mi/mo |
|---|---|---|---|---|
| Tesla Model 3 Premium RWD (2026) | 24.6 | 137 | 273 | 410 |
| Hyundai Ioniq 6 RWD 18in (2025) | 26.0 | 144 | 289 | 433 |
| Tesla Model Y Long Range AWD (2026) | 27.5 | 153 | 306 | 458 |
| Chevrolet Bolt EUV (2023) | 29.4 | 163 | 327 | 490 |
| Volkswagen ID.4 (2026) | 29.8 | 166 | 331 | 497 |
| Ford Mustang Mach-E RWD Ext (2026) | 30.7 | 171 | 341 | 512 |
| Chevrolet Blazer EV FWD (2026) | 32.3 | 179 | 359 | 538 |
| Kia EV9 Long Range RWD (2026) | 38.0 | 211 | 422 | 633 |
| Tesla Cybertruck AWD (2026) | 42.9 | 238 | 477 | 715 |
| Rivian R1T Dual Large (2026) | 44.4 | 247 | 493 | 740 |
| Ford F-150 Lightning 4WD ER1 (2025) | 47.9 | 266 | 532 | 798 |
| GMC Hummer EV Pickup 3X (2025) | 65.1 | 362 | 723 | 1,085 |
For perspective on those numbers: a typical US household uses somewhere in the region of 800-900 kWh a month. So a Model Y at 1,000 miles a month is adding roughly a third again to the total; a Hummer EV at the same mileage is nearly doubling it.
What it compares to
| Load | Rough monthly kWh | Comparable to |
|---|---|---|
| An efficient EV, 500 miles | 140-170 | A modest addition |
| An efficient EV, 1,000 miles | 270-340 | Roughly an electric water heater |
| A large EV, 1,000 miles | 420-530 | A water heater plus a dryer |
| A Hummer EV, 1,000 miles | 723 | A substantial new appliance load |
Three things that change the number
1. Your tariff, which matters most
Not the amount of energy but what it costs. A time-of-use tariff with a 2-3x peak-to-off-peak spread, charged overnight, can halve the bill impact without changing a single kWh of consumption. This is the biggest lever available and it is free to ask about. Time-of-use rates and EV charging.
2. Winter
Consumption rises in cold weather — cabin heating, battery conditioning, denser air. Expect a meaningfully higher winter bill, and note that preconditioning while plugged in moves that heating load from the battery to the wall, which is cheaper overall. Cold weather EV charging.
3. Charging losses, which you cannot avoid
Roughly 10% of metered energy does not reach the battery. That is why a calculation based on battery capacity alone understates the bill, and why the 0.9 is in the formula.
What the charger itself costs to run
Almost nothing. A Level 2 charger draws a small standby load when idle — typically a few watts — which over a month is a rounding error against the charging consumption. ENERGY STAR certification on a charger is partly about exactly this standby draw, and the certified units are measured for it.
So the honest answer to “how much does the charger add” is: the charger adds nothing meaningful. The car adds everything.
How to find your actual number
The formula gives you an estimate. A circuit-level energy monitor gives you the measurement, which is better for two reasons: it captures your real driving rather than an assumed mileage, and it captures your actual charging losses rather than a 10% allowance.
Knowing what your panel is actually doing
Emporia Vue 3 Home Energy Monitor
Monitors the charging circuit separately from the rest of the house, so you know exactly what the car is costing rather than estimating. Also finds everything else in the house that is quietly expensive, which is usually the surprise.
#ad Price as of October 5, 2026. How we make money
What is not in this number
- The installation, which is a one-off. What installation costs.
- Any comparison with gasoline, because that depends on fuel prices and the car you would otherwise have bought.
- Standing or demand charges on some tariffs, which do not scale with your charging but may be triggered by it.
- Public charging, which is a separate and usually higher cost. Home against public.
