EV Charging Cost Per Mile: How to Calculate It (Home and Public)
- EV cost per mile: (kWh/100 miles ÷ 100) × $/kWh.
- EV cost per 100 miles: (kWh/100 miles) × $/kWh.
- Don’t forget losses: real “from-the-wall” energy can be higher than what reaches the battery.
What We Know (Sourced)
EPA’s electric vehicle label documentation explains that kilowatt-hours per 100 miles is an energy unit for electricity and that it relates directly to electricity used and therefore to cost. Source: U.S. EPA — Text version of the electric vehicle label.
EPA also notes that MPGe values include charging losses and are intended to reflect energy use from the outlet in the wall. Source: U.S. EPA — Fuel Economy and EV Range Testing.
FuelEconomy.gov is the official government source for fuel economy information and tools that help consumers compare vehicles. Source: FuelEconomy.gov.
The Two Inputs You Need
1) Energy use (kWh per 100 miles)
This is the EV equivalent of “fuel consumed per distance.” If you have MPGe but not kWh/100 miles, start with the definitions first: What is MPGe? and kWh/100 miles.
2) Electricity price ($/kWh)
Use the rate you actually pay. If your utility has time-of-use pricing, the “right” rate depends on when you charge. For public fast charging, use the posted price for the station you typically use.
Formulas + Examples
Step-by-Step Method
- Get your kWh/100 miles from official label information or your vehicle’s efficiency screen.
- Choose your charging price (home rate, public rate, or a weighted mix).
- Compute cost per 100 miles and then divide by 100 for cost per mile.
- Sanity-check with real life: track a few charging sessions and miles driven to estimate your “from-the-wall” kWh per mile.
To compare EV vs gas on the same scale, see: Gas vs electric cost per mile and fuel cost per 100 miles.
Want the comparison done automatically?
Enter your MPG, kWh/100 miles, and prices to estimate annual costs.
Use the Gas vs Electric CalculatorWhat’s Next
Once you have a reasonable cost-per-mile estimate, you can use it to answer practical questions:
- How much does my commute cost per week or month?
- How do public-charging sessions change my average cost per mile?
- What is the break-even point versus a gas vehicle at my local prices?
Related guides: commute fuel budgeting and break-even MPG payback.
Why It Matters
EV efficiency metrics are designed to support cost comparisons. EPA’s electric label text explicitly links kWh/100 miles to electricity used and therefore cost, and EPA’s testing documentation explains that official MPGe accounts for charging losses. Sources: EPA EV label text and EPA testing.
Frequently Asked Questions
Should I use “battery kWh” or “from-the-wall kWh” for cost?
For budgeting, “from-the-wall” kWh is more realistic because it reflects what you pay for. EPA notes that MPGe values include charging losses to represent energy use at the outlet. Source: EPA testing documentation.
Can I compare EV cost per mile to gas cost per mile directly?
Yes. Both are just dollars per mile using your local energy price. For the gas formula, see: fuel cost per mile.
Where can I find official kWh/100 miles and MPGe data?
Look at the EPA label materials and FuelEconomy.gov. Sources: EPA label overview and FuelEconomy.gov.