What an EV Adds to Your Electric Bill

Most EV cost writing — including ours — talks in cents per mile, because that is the figure that compares cleanly with gasoline. But the question people actually ask before buying an electric car is simpler and more practical: what happens to my electricity bill?

The base arithmetic is easy. Two complications sit on top of it, and both can make the real answer worse than the simple version — which is exactly why they are worth knowing before the first bill arrives rather than after.

The base arithmetic

Two steps. First, kilowatt-hours: monthly miles ÷ efficiency in miles per kWh. We use 3.5 miles per kWhas a reference for a mid-size EV throughout this site; substitute your own from the car’s efficiency label, which DOE and EPA publish in kWh per 100 miles. Electric trucks and large SUVs are considerably less efficient; small hatchbacks are better.

Second, dollars: kilowatt-hours × your rate. The EIA reports a US residential average of 17.30 cents per kWh for 2025, which is the reference column below.

The middle row is the one most households land near. A thousand miles a month — which is a fairly typical amount of driving — is about 286 kWh, or roughly $50 a month at the national average rate. For scale, that is a substantial addition to a residential bill, comparable to adding a significant appliance, and dramatically less than the fuel it replaces. Our EV vs gas comparison does that side of it properly.

Complication one: tiered rates

The table above assumes every kilowatt-hour costs the same. For many households it does. For others it does not, because their utility bills in tiers— consumption above a monthly threshold is charged at a higher rate than consumption below it.

This matters more for EV charging than for almost any other load, because of where the car’s consumption lands. Adding a few hundred kilowatt-hours a month to an existing household total pushes a lot of it abovethe threshold, so the car’s energy gets billed at the top tier rather than the average rate. Your average cost per kWh goes up, and the marginal cost of charging — the number that actually matters — can be well above what your bill’s headline rate implies.

What to do:

• Check your bill for tier boundaries. They are usually printed, often as a baseline allowance plus an over-baseline rate.
• Estimate using the top tier rate, not the average, when working out what an EV will cost you. That is the honest number.
• Ask about an EV-specific tariff. Many utilities offer plans designed for EV owners precisely because the tier structure penalizes them. Some involve a separate meter.

Complication two: when you charge

The second complication is also the biggest opportunity. The EIA observes that some utilities offer time-of-day pricing to reduce peak demand, and that the cost to supply electricity is genuinely higher in the afternoon and early-evening peak hours — even though most customers pay a seasonal average that hides this.

For an EV owner, that is close to a free lunch. A car parked overnight is the most flexible load in the house: it does not care whether it charges at 8pm or 2am, as long as it is full by morning. If your utility offers a time-of-use rate, moving charging into the cheap window can change what the car costs you substantially — without changing a single kilowatt-hour of consumption.

Two caveats worth knowing before you switch. A time-of-use tariff usually applies to your wholehouse, so evening cooking, laundry and air conditioning move to the expensive rate too — the net effect depends on your household’s overall shape. And you need to actually schedule the charging, either in the car or in the charger. Our time-of-use guide works through both, and any smart charger will hold a schedule.

What does not affect your bill

Three things people worry about that mostly do not matter:

• Charger speed.A 48-amp charger and a 32-amp charger deliver the same kilowatt-hours to the same car; one just finishes sooner. The only monetary effect is the indirect one — finishing inside a cheap window. Do not buy amps expecting a cheaper bill; buy them for the reasons in our sizing guide.
• Standby draw.ENERGY STAR certified chargers use about 40% less energy in standby than uncertified ones, and standby runs continuously — but the absolute figure is a few watts, which is single-digit dollars a year. Worth having, not worth agonizing over. The certification is more valuable as a rebate qualifier.
• Leaving the car plugged in.A charged car sitting on the cable draws essentially nothing beyond whatever the vehicle itself decides to do — and in cold weather, leaving it plugged in is generally the cheaper option, because the car can precondition from the grid instead of the battery.

How to verify what you are actually using

Estimates are fine; measurements are better. Three approaches:

1. Compare bills.Crude but free. Look at the same month a year earlier to control for seasonal heating and cooling, and note the change in kilowatt-hours rather than dollars — rates move.
2. Read the car’s data.Most EVs report energy consumed per trip and per charging session. This tells you what went into the battery, which is slightly less than what came out of the wall, since charging is not perfectly efficient — DOE and EPA account for those AC charging losses in the efficiency label.
3. Use a charger with energy monitoring. This is the one that isolates charging from everything else in the house. The Emporia Level 2reports per-session kilowatt-hours at the wall, which is the figure your utility actually bills you for — and it lets you check this page’s arithmetic against your own reality rather than taking our word for it.

Once you have a real monthly number, the rest of the cost picture follows: our cost-to-charge guide for the per-charge detail, home vs public charging for why this number is so much better than the public alternative, and solar and EV charging if you are wondering whether to generate some of it yourself.