By EV Charge Cost Editorial Team. Published September 28, 2026, updated October 26, 2026.
Why the "price per kWh" line is not the whole story
Most bills list several per-kWh lines rather than one price. A typical bill has some mix of:
- Supply or generation: the energy itself, charged per kWh.
- Delivery, distribution or transmission: the cost of the wires, often also per kWh.
- Riders and surcharges: fuel adjustments, programs and other per-kWh add-ons.
- Taxes and fees: some are a percentage of the bill, some per kWh.
- A fixed customer charge: a flat monthly amount you pay whatever you use.
Looking at only the supply line understates what an extra kWh really costs. Dividing the whole bill by kWh overstates it slightly, because the fixed charge does not grow when you add an EV.
Step by step
- Find the total kWh used for the billing period. It is usually near the meter readings.
- Add up every charge that changes with kWh, including per-kWh delivery lines, riders and percentage-based taxes.
- Leave out the fixed monthly customer charge and one-off items.
- Divide the sum by the kWh. Multiply by 100 to get cents per kWh.
- Repeat with a summer and a winter bill if your utility has seasonal or tiered prices.
A worked example
This example is made up to show the arithmetic. Suppose a bill for 900 kWh totals $163.44, which works out to the U.S. average price of 18.16¢/kWh. Assume $15.00 of that is a fixed customer charge (an illustrative figure, not a real tariff).
- All-in average rate: $163.44 ÷ 900 kWh = 18.16¢/kWh
- Usage-based charges: $163.44 − $15.00 = $148.44
- Marginal rate for extra kWh: $148.44 ÷ 900 kWh = 16.49¢/kWh
For an EV that adds 377 kWh a month, the difference between the two rates is about $6.28 a month in this example. It is small, but it grows with a larger fixed charge, and it matters more if your bill has tiers. See tiered rates and EV charging.
How much your rate changes the EV bill
State averages from EIA give a sense of the spread. The table shows the monthly cost of 1,125 miles in a 33.5 kWh/100 mi EV at five points in the ranking.
| Point in ranking | State | Price | Per month |
|---|---|---|---|
| Cheapest state | Nevada | 12.72¢/kWh | $47.94 |
| Lower quarter | Oklahoma | 14.82¢/kWh | $55.85 |
| Middle state | Alabama | 16.33¢/kWh | $61.54 |
| Upper quarter | Pennsylvania | 21.77¢/kWh | $82.05 |
| Most expensive state | Hawaii | 47.18¢/kWh | $177.81 |
Your own rate can sit well above or below your state's average, depending on your utility and plan. The state pages show the average for each state; your bill tells you what you actually pay.
Common mistakes
- Using only the supply price. Delivery charges can be a large share of the total, so the supply line alone understates the real rate.
- Using one month. Seasonal prices, fuel adjustments and tiers can move the rate from month to month. An average of several bills is safer.
- Comparing offers on supply alone. If you shop for a supplier, the delivery part stays with your utility, so compare like with like.
Special cases
- Time-of-use plans: calculate the off-peak rate separately, since that is when the car should charge. See time-of-use rates.
- Separate supplier: in areas with retail choice, supply and delivery may come from different companies. Add both.
- Solar with net metering: the value of a kWh depends on how exported energy is credited. See solar panels and EV charging.
Once you have the number, put it into the charging cost calculator in place of the state average.