Home charging vs public charging: compare the real cost
The price per kWh is only one part of charging your EV. Your electricity contract, public charging tariffs, session fees and charging habits can all change what you pay. A comparison is useful only when it includes the same driving distance and clearly states which fees are counted.
Which charging method should you compare?
Home charging uses the electricity price relevant to your home. Public AC stations can have a separate price per kWh and a charging-card or session fee. DC fast charging can have a different tariff, and some providers also have time-based or occupancy charges. A lower kWh price does not automatically mean a lower bill when other fees apply.
What belongs in the calculation?
Start with the kWh your battery uses per 100 km and the distance you drive. Divide battery energy by (1 − the charging-loss rate) to estimate electricity purchased from the grid. Apply the relevant electricity tariff to each charging method and add the estimated session fees. Compare the resulting blend with a clearly defined alternative.
Worked example based on the Voltavena calculator
This scenario assumes 1,200 km per month, 18 kWh/100 km, 8% charging losses and a charging mix of 70% at home, 20% public AC and 10% DC fast charging.
- Driven each month
- 1,200 km
- Battery energy needed
- 216 kWh
- Electricity purchased
- 234.8 kWh
- Estimated charging sessions
- 3.4
- Cost of selected charging mix
- €73.20
- Cost of 100% public AC
- €110.80
Illustrative tariffs: home 70%, public AC 150% and DC fast 220% of the country example electricity price, rounded to two decimals. Session fees are 0, 1.50 and 3 currency units. This is not a current local price quote or a real charging schedule.
How does the charging mix affect the result?
The three shares are relative weights. If they do not sum to 100%, the calculator normalizes them. If all shares are zero, this calculator assumes 100% home charging. Energy costs and session fees are allocated by the normalized shares; a method with 0% share contributes nothing. The comparison baseline is always 100% public AC charging with its fee assumptions, not the cheapest possible charging arrangement.
Why can session fees change the answer?
A fixed fee adds to the bill for each applicable charging session. Our tool uses a simplified planning assumption of one session per 350 km driven and distributes those sessions across the selected mix. Real session counts vary with battery size, charge level and driving conditions. Time-based or occupancy charges and subscriptions are not modeled; check them separately in the actual provider tariff.
Where this estimate stops
The calculator does not read a live electricity contract, charger tariff or charging card. It excludes charger installation and financing, parking, idle fees, memberships and variable hourly prices unless you account for them yourself. Saving compared with public AC charging does not prove that home charging is cheapest in every situation. A negative saving means your selected mix costs more than the public-AC baseline under these inputs.
Common questions
Is home charging always cheaper than public charging?
No. It depends on your complete electricity price, public tariffs and fees. Compare the prices actually charged to you rather than assuming one option always wins.
Does charging efficiency change the price comparison?
Yes. Charging losses affect the amount of electricity purchased. In this simple calculator, one chosen loss percentage is applied across methods, although real losses may differ.
Does the calculator include the cost of installing a home charger?
No. The home-versus-public mix calculator shows charging expenditure. Use the separate home-savings calculator to explore a hypothetical installation payback, with its assumptions.
Try the numbers for your situation
Understand EV charging lossesBackground and pricing context
ANWB and NAF discuss variability in real charging costs. The European Commission explains public charging price transparency under AFIR. Those references are background only; the sample prices above come from Voltavena inputs, not from these sources.