Pick a model or enter your own numbers, choose a charging scenario, and see the real cost per 100 km — home electricity price pulled from Destatis' official household average, with all four scenarios compared.
Charging always draws more energy from the grid than ends up in the battery — AC charging loses roughly 12%, DC roughly 7%, to heat and conversion losses. The calculator accounts for this: energy drawn = energy to battery / efficiency, so the price you pay reflects what actually leaves the wall socket, not just what the battery gained.
The home price defaults to Destatis' official household electricity average (table 61243) — a real, independently published figure, though it blends every tariff on the market, including older and more expensive contracts. Public AC, public DC and fast-charging prices have no equivalent public data source (charging operators set their own, fragmented pricing), so those stay as editable typical averages.
Because charging isn't 100% efficient. AC charging (via a wallbox) loses roughly 12% of the energy drawn from the grid to heat and conversion; DC fast charging loses roughly 7%. The calculator always computes cost from the energy actually drawn from the grid, not just what lands in the battery — otherwise the number would understate your real electricity bill.
Typically 1.4-1.5x more per 100 km, mainly because fast-charging operators charge a premium price per kWh (often 0.55-0.79 €/kWh) compared to a home electricity tariff (around 0.40 €/kWh on official average) — DC charging is also slightly less efficient than AC, which adds a small additional gap.
In almost all cases, yes, when charging at home or on public AC — even the official household electricity average works out cheaper per 100 km than petrol at typical consumption figures. Fast charging narrows or can even close that gap, depending on current fuel and electricity prices, which is why comparing your actual charging scenario matters more than a generic EV-vs-petrol claim.