EV vs petrol cost per trip: compare the same distance
Compare electricity and fuel for a journey using consumption per 100 km, energy prices and charging fees without confusing operating cost with total ownership.
Put both vehicles on the same distance
For 180 km, an EV consuming 18 kWh per 100 km uses 180 × 18 ÷ 100 = 32.4 kWh in the battery. At 0.20 per kWh and ignoring charging losses, energy costs 6.48. A petrol car using 7 L per 100 km needs 12.6 L; at 1.50 per litre, fuel costs 18.90. Keep both prices in the same currency.
Account for charging losses and fees
If 32.4 kWh must reach the battery at 90% charging efficiency, grid use is 36 kWh and the energy cost at 0.20 becomes 7.20. Public chargers may add a session fee, time charge or different rate. Compare scenarios in the EV versus petrol calculator and the EV charging calculator.
Separate trip cost from ownership cost
The calculation excludes purchase price, depreciation, insurance, maintenance and parking. Real consumption changes with speed, temperature and terrain. The fuel economy guide explains how to compare distance-based efficiency measures; use measured consumption when available.