Use your prices, not a national promise
Public fast-charging prices vary by network, location, membership, time, and sometimes session fees. Residential prices also vary substantially by state and utility. The calculator starts with an illustrative public price and the U.S. Energy Information Administration’s forecast average residential price of 18.2 cents per kWh for 2026, but both are editable. Check the latest EIA Short-Term Energy Outlook and your utility bill.
What the calculation includes
Battery energy is distance divided by miles per kWh. Grid energy accounts for the charging loss you select. Cost is split between home and public energy using your percentage. It does not include parking fees, idle fees, charging memberships, tolls, battery preconditioning, hotel charging, or changes in efficiency caused by weather and speed.
Three ways to improve the estimate
- Use your vehicle’s recent highway efficiency rather than its combined rating.
- Enter prices from the exact networks and states on your route.
- Increase expected energy use for cold weather, high speed, elevation gain, a roof box, or towing.
