Calculating fuel cost per kilometre helps you budget accurately for your vehicle. With petrol prices ranging from €1.733/L in Spain to €2.35/L in the Netherlands, and electricity from €0.220/kWh EU average to €0.387/kWh in Germany, the calculations are straightforward but market-dependent.
This guide walks you through the exact formulas using verified 2026 fuel prices and electricity rates. You'll learn to compare petrol, diesel, and EV costs on the same basis, helping you make the best choice for your driving needs and budget.
Petrol cost per kilometre calculation
To calculate petrol cost per kilometre, divide the fuel price per litre by the vehicle's litres per 100km (or miles per gallon converted). In 2026, petrol costs €1.733/L in Spain to €2.35/L in the Netherlands. A typical petrol car achieving 8 L/100km costs €0.14-€0.19 per kilometre at the pump.
For UK drivers, petrol at £1.64/L with average fuel consumption of 7.5 L/100km equals £0.12 per kilometre. This calculation ignores road tax, insurance, and maintenance but gives you the pure fuel cost basis for comparison.
Diesel cost per kilometre calculation
Diesel cost per kilometre follows the same formula but uses diesel prices. In 2026, diesel ranges from €1.865/L in Spain to €2.326/L in the Netherlands. A typical diesel car achieving 6 L/100km costs €0.11-€0.16 per kilometre.
The fuel-saving advantage of diesel depends entirely on two things: how much less fuel the diesel engine uses, and how the two pump prices compare where you live. In some markets diesel is now more expensive per litre than petrol, which erodes or eliminates the saving. Calculate cost per 100 km with your own consumption figures and current local prices rather than assuming diesel always wins.
Electric vehicle cost per kilometre calculation
Electric cost per kilometre uses the formula: electricity price per kWh divided by vehicle efficiency (kWh per km). With EU average electricity at €0.220/kWh and typical EV consumption of 0.15-0.20 kWh/km, the cost ranges from €0.03-€0.04 per kilometre.
Even in expensive electricity markets like Germany (€0.387/kWh) or Ireland (€0.38/kWh), EVs still cost €0.05-€0.06 per kilometre, making them fundamentally cheaper than petrol or diesel alternatives.
Complete comparison chart
Here's the cost comparison across 2026 markets:
- Ireland: Petrol €0.14-€0.19/km, Diesel €0.12-€0.15/km, EV €0.05/km (electricity €0.38/kWh)
- UK: Petrol £0.12/km, Diesel £0.11-£0.13/km, EV £0.04-£0.05/km (electricity £0.263/kWh)
- Germany: Petrol €0.15-€0.21/km, Diesel €0.13-€0.18/km, EV €0.05-€0.07/km (electricity €0.387/kWh)
- Spain: Petrol €0.11-€0.15/km, Diesel €0.10-€0.13/km, EV €0.04-€0.05/km (electricity €0.267/kWh)
Spain consistently offers the lowest costs across all fuel types, while Germany shows the highest petrol/diesel prices despite having more expensive electricity.
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Frequently asked questions
How do I calculate my actual fuel cost per kilometre?
Divide your fuel price per litre by your vehicle's litres per 100km, then divide by 100. For example, €2/L petrol ÷ 8 L/100km ÷ 100 = €0.0025 per kilometre. Track your actual fuel consumption over time for the most accurate calculation.
What's the most accurate way to measure EV cost per kilometre?
Use your utility bills for home charging costs, divide total monthly electricity cost by total kilometres driven that month. For public charging, track each charging session cost divided by distance, then combine with home charging for complete picture.
Does fuel consumption vary with driving conditions?
Yes, fuel cost per kilometre varies 15-25% based on driving conditions, vehicle load, and climate. City driving and heavy loads increase consumption, while highway cruising often improves efficiency. Use realistic driving assumptions for accurate budgeting.
How does seasonal fuel price affect calculations?
Fuel prices fluctuate seasonally, typically 5-10% higher in winter due to heating demand. Electricity prices show smaller seasonal variations. Update your cost calculations quarterly for most accurate budgeting.
Should I include maintenance in cost per kilometre calculations?
Pure fuel cost per kilometre gives you baseline transportation costs. For complete picture, add maintenance (about 5-7 cents per km), insurance, and depreciation. EV maintenance costs are typically 30-50% lower than equivalent petrol cars.
How do I compare different vehicle types using this metric?
Calculate fuel cost per kilometre for each vehicle type using their specific fuel/electricity price and efficiency. EVs consistently show 60-70% lower costs than petrol cars and 50-60% lower than diesel vehicles across most markets.