EV Charging Calculator Methodology
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The formulas, units and assumptions used throughout the site are documented here so every result can be reproduced independently.
Charging-session cost
Battery energy added equals usable battery capacity multiplied by the change in state of charge. Wall energy equals battery energy divided by charging efficiency. Session cost equals wall energy multiplied by the applicable electricity price per kWh.
Cost per distance
Cost per 100 km equals vehicle consumption divided by charging efficiency and multiplied by electricity price. Cost per mile applies the equivalent consumption per mile.
Charging time
Ideal AC time equals wall energy divided by the lower of charge-point power and the vehicle onboard-charger limit. DC charging is not linear because power normally tapers as state of charge rises.
Limitations
Examples normally use 90 percent AC efficiency unless stated otherwise and exclude standing charges, subscriptions, parking, connection fees and idle fees.