Car & driving
How much does a road trip cost in fuel?
Liters and money needed for a trip based on distance, car consumption and fuel price — one way or round trip.
Quick answer
The cost of a car trip is three numbers multiplied together — distance, consumption, fuel price — and the only one people get wrong is consumption. The official figure was measured in a laboratory; your real number on the motorway at 130 km/h is typically 15-25% higher, and city stop-and-go can double it. The most honest figure lives in your trip computer: reset it, drive a full tank, and use that average.
Trip cost
8.53
- Fuel needed
- 19.5 L
- Cost per 100 km
- $6.18
Real consumption beats the brochure figure: motorway at 130 km/h adds 15-25% over the official number, city traffic even more, while steady 100-110 km/h can match it. A roof box adds 10-20%, underinflated tires 3-5%. Check your car’s trip computer average over a full tank for the most honest number to enter here.
How it works
For trip planning, the useful mental unit is cost per 100 km, which the calculator shows alongside the total: a 6.5 L/100 km car at €1.85 per litre costs €12 per 100 km, so a 600 km holiday round trip is about €72 of fuel before tolls. Speed is the biggest lever you control on the day — dropping from 130 to 110 km/h cuts consumption roughly 20% and costs surprisingly little time on all but the longest legs. Tire pressure, roof loads and 200 kg of luggage each nibble a few percent more.
Frequently asked questions
How do I convert km/L to L/100km?+
Divide 100 by one to get the other: 15 km/L = 100 ÷ 15 = 6.7 L/100 km, and vice versa. The calculator accepts both units, so enter whichever your car shows. As reference points: 5 L/100 km (20 km/L) is excellent, 6-7 is a good modern car, 8-10 is an SUV or spirited driving, above 12 is sports car or heavy traffic territory.
Why does my car consume more than the official figure?+
Official WLTP figures come from a standardized lab cycle with gentle accelerations and moderate speeds — no 130 km/h motorway, no cold starts on school runs, no air conditioning battling summer heat. Expect real-world consumption 10-25% above official, more in winter (cold engines run rich for the first kilometres) and with short urban trips where the engine never warms up.
Does driving slower really save that much fuel?+
On the motorway, yes — air resistance grows with the square of speed, so 130 km/h needs roughly 40% more power than 110. In practice, dropping cruise speed from 130 to 110 cuts consumption about 20% and adds only 8 minutes per 100 km. The other big saver is anticipation: reading traffic to avoid braking and re-accelerating is worth 10-15% in mixed driving, free.
Should I split fuel costs with passengers, and how?+
The fairest simple method: total fuel (this calculator) plus tolls, divided by all occupants including the driver. Carpooling platforms typically suggest a per-km rate slightly above pure fuel cost — reasonable, since tires, oil and depreciation also wear with the kilometres. What matters is agreeing the number before the trip, which is exactly what this page is for.
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