Fuel Distance Calculator
How far can you go on the fuel you have? Multiply the fuel in the tank by the vehicle’s efficiency and you have the range. This calculator does that in metric or imperial units, accepts efficiency as km/L, mpg, or L/100 km, and adds the trip cost when you enter a fuel price. A second mode reverses the question: for a planned trip distance, how much fuel will you need and what will it cost.
How to use this calculator
The Trip range tab answers “how far can I go”: enter the fuel in the tank, its unit, your vehicle’s efficiency, and the efficiency unit. Add an optional fuel price to see the trip’s fuel cost and the cost per 100 km. The Fuel needed tab reverses it: enter a planned trip distance and efficiency to find the fuel required in liters and gallons, plus the estimated cost.
The fuel distance formula
Distance = Fuel amount × Fuel efficiency, with matching units: liters with km/L, gallons with mpg. For L/100 km figures, convert first: km per liter = 100 ÷ (L/100 km). The reverse is fuel needed = distance ÷ efficiency. Trip cost is simply fuel used × price per unit.
Worked examples
Range: 40 liters at 15 km/L gives 40 × 15 = 600 km (372.8 miles). At $1.50 per liter the tankful costs $60.00, or $10.00 per 100 km. Imperial: 10 gallons at 25 mpg gives 10 × 25 = 250 miles. With a consumption figure instead: 40 liters at 7.5 L/100 km gives 40 ÷ 7.5 × 100 = 533.3 km. Fuel needed: a 500 km trip at 15 km/L requires 500 ÷ 15 = 33.33 liters (8.81 gallons), about $50.00 at $1.50 per liter.
Frequently asked questions
How do you calculate fuel distance?
Multiply the fuel quantity by the efficiency: 10 gallons × 25 mpg = 250 miles. Keep the units matched.
How much fuel do I need for a trip?
Divide the trip distance by your efficiency. A 500 km trip at 15 km/L needs 33.33 liters. The Fuel needed tab does this and adds the cost.
How do I convert mpg to L/100 km?
Divide 235.214 by the mpg figure: 25 mpg = 9.41 L/100 km. The tool accepts all three efficiency units directly, so you rarely need to convert by hand.
What is a typical fuel efficiency?
Most gasoline cars fall between 20 and 30 mpg (about 8–12 L/100 km). Hybrids do better, trucks and SUVs worse. Use your car’s dashboard average or manual figure for the most honest estimate.
Should I trust the range down to the last liter?
No. Efficiency varies with speed, load, terrain, and weather, and running a tank dry risks the fuel pump. Treat the result as a maximum and plan refueling with a comfortable reserve.
How is trip cost calculated?
Fuel used × price per liter or gallon. For the range tab, that is the whole tank; for the fuel-needed tab, it is the trip’s share.
Does this work for electric vehicles?
Not directly: EVs use kWh per 100 km rather than liquid fuel. The math is analogous (range = battery ÷ consumption), but this tool’s units are fuel-based.
Why do my units have to match?
Because the formula multiplies them. Mixing gallons with km/L silently produces a wrong number, which is why the tool converts everything internally before multiplying.
What competitors miss
We read the seven top-ranking fuel distance pages before writing this one. Every tool computes distance from fuel and efficiency, and only one adds trip cost. None of them offers the reverse calculation as a real tool mode: the one rival that documents “fuel needed” does it in a FAQ paragraph, not in the calculator. None accepts L/100 km as an efficiency input even though much of the world buys fuel that way. This page keeps the classic range calculation identical to the original tool, adds the fuel-needed reverse mode with cost, accepts all three efficiency units, and shows cost per 100 km for budget planning.