gpsspeedometer.io

Travel tool · Four-country units

Road Trip Cost Calculator

Plan fuel cost and driving time with miles or kilometres, US or imperial MPG, L/100 km and your local fuel price.

Updated 2026-08-12

Enter your distance, average speed, fuel economy and fuel price. The calculator returns driving time, fuel needed and estimated trip fuel cost in one step.
Estimated trip$35.00 · 5 hr driving

10.0 US gal / 37.9 L of fuel

Fuel-only estimate. Tolls, parking, food, accommodation, traffic and stops are not included.

What the trip estimate includes

The calculator combines distance, cruising speed, fuel economy and fuel price. It shows driving time before stops, fuel required and total fuel cost. Add your expected stops separately for a realistic arrival time.

US MPG and imperial MPG are not the same. One imperial gallon is larger, so the same vehicle produces a higher MPG number in the UK. Choose the correct economy unit rather than reusing a dashboard figure under the wrong standard.

Planning assumptions by country

CountryCommon distanceEconomy formatFuel price
United StatesMilesUS MPGUSD per US gallon
United KingdomMilesImperial MPGGBP per litre
CanadaKilometresL/100 kmCAD per litre
AustraliaKilometresL/100 kmAUD per litre

Why real trips take longer

  • Traffic and urban approaches reduce average speed below the motorway limit.
  • Fuel, food and rest stops are not included in pure driving time.
  • Weather, roadworks and towing can increase both time and fuel use.
  • EV drivers can use the same time estimate, but should use the EV charging stop calculator for energy and charging.

Frequently asked questions

How do I calculate road trip fuel cost?

Convert the distance and fuel economy into gallons or litres used, then multiply by the local fuel price. This calculator performs the unit conversion automatically.

Does the calculator include stops?

No. Driving time is distance divided by average moving speed. Add food, fuel, charging and rest stops to get a door-to-door estimate.

What average speed should I use?

For a motorway-heavy trip, 55-65 mph or 90-105 km/h is usually more realistic than the posted maximum once slower sections are included.

Can I use UK imperial MPG?

Yes. Select Imperial MPG. Do not select US MPG because the gallon sizes differ.

Related tools and guides

Speed, distance and time Solve any missing trip variable. Average speed calculator Calculate actual speed from elapsed time. MPG calculator Convert MPG, L/100 km and km/L. EV charging stops Estimate how speed changes EV arrival time.

Official sources

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