How do I calculate a trip cost?

Multiply distance by consumption (L/100 km or kWh/100 km), then by energy price. AutoSuivi also shows cost per kilometre.

Does it handle petrol and electric?

Yes. You can estimate a petrol/diesel trip (litres) or an electric one (kWh), with total cost and cost per km.

Why cost per kilometre?

Cost per km compares trips or powertrains at equal distance, regardless of purchase price.

Does it include tolls, parking and wear?

No. The tool only counts energy (litres or kWh). For the full cost (depreciation, insurance, servicing), use the TCO calculator.

Trip cost

Trip details

How do I find my consumption?

Check the vehicle handbook
Check the trip computer
Calculate: (Litres / Distance) × 100

How do I find my consumption?

Check the dashboard (kWh/100 km displayed)
Check the manufacturer spec sheet
Typical range: 14–22 kWh/100 km depending on the model
Typical home charging rate: ~ €0.20/kWh

Fill in the form to calculate your trip cost

How trip cost is calculated

Trip distance

L ou kWh

Consumption per 100 km

€

Price per litre / kWh

€/km

To compare

Formula

Combustion: (distance × L/100 km / 100) × price per litre.

Electric: (distance × kWh/100 km / 100) × price per kWh.

Cost per kilometre is the total divided by distance. That is the useful figure to compare petrol, diesel and electric on the same trip.

Use real consumption (trip computer), not the WLTP sheet.
Motorway: +1 to +2 L/100 km, or +4 to +8 kWh/100 km depending on wind and speed.
Return trip: double the distance, leave consumption unchanged.

kWh price: the trap

The same EV can cost 3 to 4 times more per km depending on where you plug in.

Home off-peak: often €0.15–0.20/kWh
Public AC charger: €0.30–0.45/kWh
Motorway rapid charger: €0.45–0.70/kWh

Run two simulations (home vs motorway) rather than an invented average. Detail in the charging-cost guide.

Example 1 — Paris → Lyon, 465 km, petrol

6.8 L/100 km at €1.85/L → 31.6 L → €58.50 of petrol, or €0.13/km. This ignores tolls (~€25–40 depending on the route) and wear. For the “real” weekend cost, add them by hand or use TCO.

Example 2 — same trip, electric

18 kWh/100 km. Home charging at €0.18/kWh before departure: 83.7 kWh → €15.07 (€0.03/km). If 40% of the energy is taken from a charger at €0.55/kWh, the trip moves towards ~€30. The gap with petrol is still wide, but it is no longer “×4”.

Limits. The tool only counts energy. Tolls, parking, AdBlue, tyres and depreciation are out of scope. The “saving vs combustion” comparison on the electric tab uses a fixed reference (7 L/100 km at €1.85/L): replace it with your own combustion simulation if your car uses more or less.