Find the cheapest EV charging window from published day-ahead electricity prices, including your tariff and charging losses.
Today and available prices for tomorrow · EUR · bidding-zone time. Tomorrow’s prices appear only after publication; this is not a long-term forecast.
Illustrative planning values, not a current supplier or country tariff. Additions are net; standing and session fees are gross. Enter your contract values, including when changing bidding zone.
Fetching current spot prices …
Find the cheapest published price intervals within a window at constant charging power.
Bidding zone, energy, charging power, efficiency, start/end time and markup, grid fee, levies and VAT.
The bidding zone selects the day-ahead price series and is not automatically identical to the residence. Efficiency and power determine how many intervals are needed, while surcharges and grid fees can change which periods are cheapest.
Required grid energy is assigned to intervals; cost is the energy-weighted sum of spot price and all surcharges.
30 kWh in the battery at 90% efficiency and 11 kW requires 33.33 kWh from the grid and about 3.03 h.
Sources and limits: Energy-Charts/SMARD price series; only published intervals are used and no long-term forecast is extrapolated.
Find the cheapest published price intervals within a window at constant charging power.
Energy calculators balance quantities over time and separate useful energy, losses and grid import. This matters because power is instantaneous while energy is its time integral.
Required grid energy is assigned to intervals; cost is the energy-weighted sum of spot price and all surcharges.
Bidding zone, energy, charging power, efficiency, start/end time and markup, grid fee, levies and VAT. The bidding zone selects the day-ahead price series and is not automatically identical to the residence. Efficiency and power determine how many intervals are needed, while surcharges and grid fees can change which periods are cheapest.
Select the bidding zone, enter the required energy amount, charging power, efficiency and the desired time window plus any surcharges (grid fee, levies, VAT). The calculator finds the cheapest published price intervals within the window for the required grid energy.
30 kWh in the battery at 90% efficiency and 11 kW requires 33.33 kWh from the grid and about 3.03 h.
The bidding zone selects the day-ahead price series and is not automatically identical to the residence. Efficiency and power determine how many intervals are needed, while surcharges and grid fees can change which periods are cheapest. An annual value describes a scenario, not a guarantee for every day. Efficiency, coincidence, temperature, driving profile and tariff assumptions can change practical results more than rounding.
Energy in kWh, power in kW, time in hours, price in ct/kWh or €/kWh.
Planning the cheapest charging window for an electric vehicle under a dynamic electricity tariff, or estimating charging cost for a known energy amount within a flexible time window.
Energy-Charts/SMARD price series; only published intervals are used and no long-term forecast is extrapolated.
Common mistake: Don't equate battery energy with required grid energy – charging losses increase the energy that must be drawn from the grid above what arrives in the battery. Don't choose too narrow a time window; if required charging time exceeds the available window, no valid solution can be found.
The calculator uses published day-ahead price series from Energy-Charts or SMARD for the selected bidding zone, not an in-house forecast or estimate of future prices.
The calculator selectively picks the cheapest intervals within the whole window, so a larger window can potentially lower total cost but never raises it above a smaller window's result.
No, the pure spot price reflects only the wholesale price; grid fee, levies, VAT and supplier markup must be entered separately as surcharges.
Grid energy = battery energy / efficiency. Charging time = grid energy / grid power. Gross prices are weighted by grid energy in each occupied interval; partial intervals are prorated.
Gross price = [spot price × (1 + percentage markup) + grid charge + levies + supplier addition] × (1 + VAT). EUR/MWh ÷ 10 gives ct/kWh.
90% efficiency means losses of 10% of grid energy. The default 10 + 5 + 2 ct/kWh and 19% VAT are editable examples. Monthly standing charges are shown separately and cannot be saved by shifting charging.
Negative spot prices are preserved; additions may still make retail prices positive. Percentage markups also multiply negative prices. Time-varying grid charges, price floors, idle fees, and vehicle-specific charging curves are not included.
Energy-Charts provides the selected zones under CC BY 4.0 using Bundesnetzagentur / SMARD data. Regional zones such as NO2 or SE4 do not represent the entire country. All calculations use euros, including outside the euro area.
The optimum applies only to published intervals within the selected window at constant grid power. Prices are not extrapolated. Paused charging requires a controllable charger; this calculator does not control devices.
Energy-Charts API ↗