How home EV charging cost is calculated
The energy needed at the battery equals miles driven divided by the vehicle's efficiency in miles per kWh. The energy drawn from the wall is slightly higher because of losses in the charger and cable, typically 5–15%. Multiplying wall energy by the electricity unit rate gives the charging cost.
Home charging typically costs significantly less per mile than public rapid charging. Most drivers charge overnight on a standard tariff or a dedicated off-peak EV tariff, which can reduce running costs further.
kWh at battery = Miles / Efficiency (mi/kWh)
Energy consumed by the vehicle for the miles driven.
kWh from wall = kWh at battery / Charger efficiency
Actual electricity drawn, accounting for charger losses (typically ~90% efficient).
Charging cost = kWh from wall × Electricity tariff
Total cost in your local currency.