Free tool

Trip gas money, door to door

Type where you’re headed, compare the toll route against the free one, pick your car — and get the gas money this drive will actually take.

Route (or enter a distance below)

Your car

Fuel price

Total fuel cost
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How the fuel cost is worked out

  1. Real road distance. Routing runs on OpenStreetMap’s road network (Valhalla engine): one route optimised for speed, one that prefers avoiding toll roads.
  2. Convert economy to L/100km. MPG figures use the exact gallon and mile definitions, so UK and US MPG don’t get mixed up.
  3. Fuel used = distance × L/100km ÷ 100, cost = fuel × price per litre. Gallon prices are converted before multiplying. Where we have live official prices (Spain, France, Italy, Australia) or the US state average, the price field is prefilled from your starting point.

Want the figure in different units? Use the MPG to L/100km converter, or see what a full tank costs with the tank calculator. Find the cheapest station before you set off with the station finder.

Frequently asked questions

How do you calculate the fuel cost of a trip?
Fuel cost = (distance ÷ 100) × fuel consumption in L/100km × price per litre. Enter a start and destination and we measure the real driving distance on the road network; if your economy is in MPG, it is converted to L/100km. Unit conversions are handled for you, in any currency.
Does avoiding toll roads save money?
Sometimes. The toll-free route is usually longer and slower, so it burns more fuel — the calculator shows both routes side by side with the fuel cost of each, so you can weigh the extra fuel and time against the toll price you’d pay. Note the toll fee itself isn’t included (there’s no free source for toll tariffs), only the fuel difference.
How do I know my car’s fuel consumption?
Three options here: pick a vehicle class preset (typical real-world figures), search your exact model in the car picker (based on official US EPA test data), or enter a figure yourself — the most accurate is your own measured consumption: brim the tank, drive normally, brim again, divide fuel by distance.
Why is my real-world fuel cost higher than the estimate?
Official economy figures are measured in ideal conditions. City driving, cold weather, a roof box, low tyre pressure, hard acceleration and a full load all push real consumption up — often 10–30% above the quoted figure. Use your own measured MPG for the most accurate result.
The CheapGas app

The cheapest pump, before you leave the house.

Everything on this site plus price-drop alerts, saved stations on your routes, and a fill-up log that shows your real cost per mile over time.

Coming soon