Fuel Stops Calculator — How Many Gas Stops on a Road Trip?
Plan how many fuel stops a road trip needs and where to make them, from the distance, tank size, fuel consumption, starting fuel level and the reserve you keep — in km and litres or miles and gallons.
How it works
fuel per km = L/100 km ÷ 100 (or per mile = 1 ÷ mpg) · distance per fill-up = tank × (1 − reserve) ÷ fuel per km · first stop = tank × (start level − reserve) ÷ fuel per km · stops = ⌈(trip − first stop) ÷ distance per fill-up⌉ · fuel used = trip × fuel per km
The calculator assumes you leave with the tank at the level you set, drive until it falls to your reserve, fill up completely and repeat. Keeping a reserve of 10–20% covers gaps between stations, detours, headwinds and the gauge's optimism. On remote routes use a larger reserve or plan stops by town, and remember that fuel consumption rises at high speed, with a loaded car, a roof box or a trailer.
Worked example
A 900 km trip in a car with a 50 L tank using 7 L/100 km, leaving full and refuelling at 15%: each tank covers 50 × 0.85 ÷ 0.07 = 607 km, so you need 1 fuel stop, at about 607 km. The trip uses 63.0 L; you buy 42.5 L on the way and arrive with 29.5 L in the tank.
Sources: US DOE fueleconomy.gov — Driving more efficiently · Natural Resources Canada — Fuel-efficient driving techniques
Frequently asked questions
How do I work out how many gas stops I need?
Divide the trip distance by the distance you can drive on one tank down to your reserve, after subtracting the first leg on the fuel you start with, and round up. This calculator does it and lists where each stop falls.
How much fuel reserve should I keep?
About 15% (roughly a quarter of the gauge on many cars) is a comfortable default. Use 25% or more in remote areas, in winter, or where stations close at night.
How far can I drive on one tank?
Tank size ÷ consumption: 50 L at 7 L/100 km is about 714 km to empty, or 607 km if you stop with 15% left. In the US, gallons × mpg gives the miles.
Does driving faster mean more fuel stops?
Yes. Above about 90 km/h (55 mph) air drag rises sharply; going from 100 to 130 km/h can raise consumption by 20–30%, shortening each leg.
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This calculator is for educational purposes. Double-check important results before acting on them.