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Amperecalc

Mobility

What does your electricity cost per 100 kilometres?

The cost of an electric car depends less on its consumption than on where it is charged. Between a home wallbox on solar power and rapid charging on the motorway there is easily a factor of five.

How we calculate

Calculation model

  1. 01

    Mileage and consumption give the energy at the wheel; charging losses are added per charging type.

  2. 02

    Charging shares are weighted and priced at their respective unit rates.

  3. 03

    Solar power from your own array is valued at its levelised cost, not at the grid price.

  4. 04

    The combustion comparison converts fuel consumption and price onto the same mileage.

Good to know

  • AC charging loses roughly 10 to 15 percent between meter and battery, DC charging about 5 to 8 percent.
  • In winter, consumption typically rises by 20 to 30 percent — more on predominantly short trips.
  • The German GHG quota still pays an annual premium for registered electric vehicles, though its value has fallen sharply.

Law & subsidies

What applies in Germany

Regulation determines the limits and tariffs this calculator works with.

Bidirectional charging: not banned, but still awkward

Feeding electricity from an electric car back into the house is not prohibited in Germany. What blocks it is certification, metering and the treatment of levies.

This is the most frequently misreported point in the field. It is not "forbidden" — it is regulatorily unfinished, and the position is moving quickly.

Show details

A bidirectional wallbox exports into the house circuit and therefore counts as a generation unit. It must be certified to VDE-AR-N 4105 and registered with the grid operator. For a long time, certified vehicle and wallbox combinations simply did not exist.

The second obstacle is metering: vehicle-to-home needs a metering concept that separates drawn from returned electricity, otherwise the same kilowatt hour risks being charged grid fees, levies and taxes twice.

Third, § 14a of the Energy Industry Act applies: wallboxes above 4.2 kW are controllable consumers, which earns reduced grid fees but lets the operator throttle them.

For the calculators here that means we deliberately do not model vehicle-to-home as a revenue item. Anyone counting on it should get the certification of their specific vehicle and wallbox pairing confirmed in writing first.

This compilation is orientation, not legal advice. Rules in this field change several times a year — check the linked primary source before you invest, or ask a certified specialist.
See all regulatory topics

Frequent questions

Answered briefly.

Why don't you value solar power at zero cents?

Because every self-charged kilowatt hour has an alternative: it could have been exported or used elsewhere in the house. What is charged is the forgone benefit — the feed-in tariff, or the levelised cost.

Is a wallbox worth it?

Above roughly 8,000 km a year, almost always. The price gap between household electricity and public AC charging is 15 to 20 cents per kilowatt hour, which typically pays back a wallbox in two to four years.

Is an electric car cheaper than a combustion car?

On energy cost, almost always, provided most charging happens at home. With exclusively rapid charging, an efficient diesel can match or beat it. The calculator shows both cases side by side.

Rooftop PV calculator

Yield, self-sufficiency and return of a rooftop array over 25 years.

Tariff comparison

Standing charge, unit rate and bonus netted out over two years.

Carbon footprint

Electricity, heat, mobility and diet — and what each measure actually achieves.

All results are model calculations based on your inputs and statistical reference data. They do not replace individual professional planning.

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