Estimate trip fuel and cost with km and L/100 km or miles and US MPG, including round trips.
Enter values, then calculate.
How the calculation works
Choose units before entering distance, efficiency and price per fuel unit. Metric fuel = km × L/100 km ÷ 100. US fuel = miles ÷ US MPG. Total cost = fuel × unit price. Round-trip mode doubles the entered one-way distance. Cost per distance uses that total distance; at zero distance it is shown as unavailable.
Example and verification
500 km at 8 L/100 km needs 40 L; at 1.50 per L the cost is 60.00. The original US example, 300 miles at 25 MPG and 3.50 per US gallon, needs 12 gallons and costs 42.00.
Software checks cover the example, invalid input, zero or boundary cases, and reset in Chromium. No physical measurements or all-browser certification are claimed.
Scope and limitations
US MPG uses the US liquid gallon, not the larger imperial gallon. Switching units clears distance, efficiency and price to prevent accidental reuse in different units. Actual fuel use varies with traffic, speed, terrain, load and conditions. Tolls, parking and maintenance are excluded; no live fuel prices are fetched.
Common questions
Should I enter one-way or total distance?
Enter one-way distance only when the round-trip option is checked. Otherwise enter the total route distance.
Technical references
Related calculators
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Maintained by GadgetsFocus. Updated 2 October 2026 with AI-assisted writing and translation review; no human native-speaker or clinical review is claimed.