Electric mobility
Calculate EV trip energy before trusting a charging-stop plan
A useful EV estimate starts with energy and an explicit reserve. A useful route also needs compatible, reachable charging sites with current access information. Those are related jobs, but one does not establish the other.
Keep starting energy and arrival reserve visible
In the illustrative default, 500 km at 18 kWh per 100 km requires 90 kWh from the battery. A usable 75 kWh battery starting at 90% contains 67.5 kWh. A 15% arrival reserve is 11.25 kWh.
Trip demand plus reserve is 101.25 kWh. Subtracting starting energy leaves 33.75 kWh to add to the battery. A lower starting charge or higher measured consumption changes that number. The model rejects a starting percentage below the selected reserve.
The meter and battery need not show the same energy
At an entered grid-to-battery efficiency of 90%, adding 33.75 kWh requires 37.5 kWh from the grid. At an illustrative USD 0.40 per grid kWh, the additional energy costs USD 15.00.
Connection, parking, idle and time fees are not hidden inside that unit price. Enter an effective price that matches your comparison or keep those charges in a separate cost record. The starting battery energy also has a cost; this result reports only additional charging needed during the modeled journey.
Average charging power matters more than the sign
At an assumed average 75 kW delivered to the battery, 33.75 kWh takes 27 minutes of energy transfer. This excludes detours, waiting, plugging in and other stops. A peak charger rating does not establish the average power your vehicle will receive.
The session count is an energy-only lower bound using the entered charge limit and reserve. It does not establish where those sessions are possible, that a charger is working, or that the required connector is available.
Treat station evidence as another input
Check connector compatibility, access restrictions, status timestamp, tariff and a fallback before relying on a candidate station. Official directories collect records through several methods and update schedules; a directory listing alone is not a reservation or real-time availability proof.
The current tool supplies no route or station feed. Use it to inspect energy assumptions and compare cases, then verify an actual journey with suitable current routing and operator information.
Primary references
Authored 2026-10-29. Arithmetic examples are covered by local regression tests. New workflow guides remain outside the indexing allowlist pending editorial and applicable specialist review. Examples use the assumptions stated here; authority guidance can change.