Road trips
Fuel-Cost Calculator
Estimate the cost of your road trip. Easily handle conversions between metric and imperial units (MPG vs L/100km) and split the cost among passengers.
- Price
- Free · no signup
- Reviewed
Trip Details
Vehicle & Fuel
Passengers & Extras
Cost Estimate
Enter distance, efficiency, and fuel price to calculate costs.
How it works
The calculator standardizes all units into a metric baseline (Kilometers and Liters) to compute the total fuel consumed, then converts the final amounts back to your preferred display units.
Formulas:
MPG (US) to L/100km = 235.21 / MPGMPG (UK) to L/100km = 282.48 / MPG1 US Gallon = 3.785 Liters1 Imperial (UK) Gallon = 4.546 Liters
Worked example
A 500-mile round trip (1,000 miles total) in a car that gets 25 MPG (US) with fuel costing $3.50 per US gallon will require 40 gallons of fuel. The fuel cost is $140. Split among 4 passengers, it's $35 each.
Limitations
This calculator provides a static estimate. Real-world fuel efficiency changes based on driving speed, AC usage, tire pressure, and elevation. Electric vehicle (EV) charging time and dynamic kw/h costs are not currently supported by this specific tool layout.
Frequently asked questions
Does the calculator double the tolls and parking for a round trip?
No. We assume the values you enter for Tolls and Parking are the total you expect to pay for the entire journey. We only double the distance for a round trip.
What is the extra distance buffer?
When road tripping, you often drive extra miles for food, detours, or getting lost. Adding a 5% to 10% buffer makes your fuel estimate much more realistic.