Fuel and trip cost: working out what a journey costs

Fuel for a trip

litres = distance in km × consumption (L/100 km) ÷ 100
fuel cost = litres × price per litre

Example: a 450 km trip in a car using 7.5 L/100 km needs 450 × 7.5 ÷ 100 = 33.75 litres. At an example price of 3,000 Toman a litre, the fuel costs 101,250 Toman. For a return trip, double it.

Converting consumption figures

Some people measure kilometres per litre instead. To convert: L/100 km = 100 ÷ (km per litre). A car that does 12 km per litre uses 100 ÷ 12 ≈ 8.33 L/100 km.

Why real use is higher

Air conditioning, heavy loads, high speed, city traffic and mountain roads all raise consumption. Add a margin of 10–20% to be safe.

The whole trip budget

• Fuel and tolls
• Accommodation per night
• Food per person per day
• Tickets and activities
• A contingency of 10–15% for the unexpected

Tools for this

• Fuel and trip cost
• Travel budget planner

Fuel prices in the example are illustrations; use the price you actually pay.