Road Trip Fuel Cost Calculator
Calculate the total fuel cost for a road trip from distance, fuel efficiency, and fuel price.
How to use this tool
- Enter the total trip distance in kilometres.
- Enter your car's fuel efficiency in L/100km (found on the trip computer or manual).
- Enter the current fuel price per litre.
- The calculator shows total litres consumed and the fuel bill for the trip.
Estimate how much fuel your road trip will use and what it will cost before you leave.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Fuel used (L) = distance (km) × efficiency (L/100 km) ÷ 100
Fuel cost ($) = fuel used (L) × price ($/L)
How it works
This calculator converts a route distance and fuel efficiency rating into the total litres of fuel consumed, then multiplies by the pump price per litre to give total cost. Efficiency is expressed in the European L/100 km convention, where a lower number means better economy. The result assumes constant driving conditions; real-world costs will vary with driving style, traffic, hills, and vehicle load.
Worked example
- Distance = 600 km, fuel efficiency = 9 L/100 km, fuel price = $1.75/L
- Fuel used = 600 × 9 ÷ 100 = 54 L
- Fuel cost = 54 × $1.75 = $94.50
Fuel used = 54 L, total fuel cost = $94.50
Common mistakes to avoid
- Entering highway fuel efficiency without accounting for city driving, heavy traffic, or mountainous terrain. Real-world efficiency on a mixed road trip can be 10-20% lower than the highway EPA rating.
- Using total distance one-way when calculating a round trip. The calculator takes total distance, so for a round trip you must enter distance times 2.
- Forgetting to update the fuel price to current local pump prices. The default or remembered price may differ significantly from actual prices at the destination, especially across state or country borders.
Key terms
- Fuel efficiency (L/100 km)
- The number of litres of fuel a vehicle consumes per 100 kilometres driven; a lower value indicates better economy.
- Fuel price ($/L)
- The cost of one litre of fuel at the pump, used to calculate total spend.
- Combined fuel economy
- An official average of city and highway fuel efficiency ratings used to estimate real-world consumption.
- MPG equivalent
- Miles per gallon — the fuel efficiency unit common in the US; 9 L/100 km ≈ 26.1 MPG (US).
- Variable fuel costs
- Real-world fuel consumption can differ from the rated figure due to speed, load, terrain, tyre pressure, and air conditioning use.
Frequently asked questions
- How do I calculate road trip fuel cost?
- Multiply distance (km) by efficiency (L/100km) and divide by 100 to get litres used. Then multiply litres by the fuel price per litre.
- What is a good fuel efficiency for a road trip?
- A fuel-efficient car uses 5–7 L/100km on the highway. Average family cars use 8–10 L/100km. SUVs and trucks may use 12–15 L/100km.