Quick answer: A 400 km trip in a car that uses 8 L/100 km needs 400 × 8 ÷ 100 = 32 litres; at 2.33 a litre that is 74.56.
How it's calculated
Fuel (litres) = distance (km) × consumption (L/100 km) ÷ 100. If you know your car's economy in km per litre instead, fuel = distance ÷ km/L. The two units convert with 100 ÷ x: 8 L/100 km is 12.5 km/L.
Cost = litres × price per litre. Fuel prices in the Gulf are set monthly or periodically (for example by Aramco in Saudi Arabia and the UAE Fuel Price Committee), so enter the current price for your grade of petrol; the 2.33 here is only a sample.
Real consumption depends on speed, air conditioning, load and traffic. Your car's trip computer, or a full-tank test with the fuel economy calculator, gives a better figure than the brochure.
Worked examples
- 400 km, 8 L/100 km, 2.33 per litre: 32 L × 2.33 = 74.56
- Same trip there and back: 64 L × 2.33 = 149.12
- 250 km at 14 km/L, 2.18 per litre: 250 ÷ 14 = 17.86 L → 38.93
Frequently asked questions
How do I find my car's fuel consumption?
Fill the tank, reset the trip meter, drive normally, then fill up again: litres added ÷ km driven × 100 is your L/100 km. The fuel economy calculator does this for you.
Is L/100 km the same as km/L?
No, they are inverses: L/100 km is fuel per distance (lower is better), km/L is distance per fuel (higher is better). Divide 100 by one to get the other.
Does air conditioning use much fuel?
It adds to consumption, especially in hot weather and city driving. Use your real measured figure if you can.
How do I split the fuel cost between passengers?
Divide the total by the number of people. A 400 km trip at 8 L/100 km and 2.33 a litre comes to 74.56, so four friends pay 18.64 each.
Does driving faster use more fuel?
Yes, and more than most people expect. Air resistance climbs steeply with speed, so 140 km/h burns noticeably more per kilometre than 100 km/h. A steady speed and gentle acceleration save the most.
Is the price per litre the same for every grade?
No. 95 and 98 cost more than 91, so enter the price of the grade you actually fill up with.