Interactive fuel economy converter and trip planner
Fuel Consumption Converter and Cost Planner
Convert fuel economy units, estimate trip and annual fuel costs, measure real consumption from a fill-up, and compare two vehicles with transparent formulas.
7 fuel economy units · trip cost · range · CO₂ estimateConvert any fuel economy value
Enter one value to see L/100 km, US and Imperial MPG, km/L, miles/L and gallons per 100 miles together.
Plan fuel, cost, range and emissions
Use your real average consumption when possible. The optional adjustment can account for traffic, weather, roof racks, load or air conditioning.
Calculate real consumption from a fill-up
For the most consistent result, fill the tank, reset the trip meter, drive normally, then refill to a similar level and enter the distance and fuel added.
Compare two vehicles or driving scenarios
Use the same annual distance and fuel price to compare consumption, fuel volume, annual cost and estimated tailpipe CO₂.
Fuel economy result
Your fuel profile
The same consumption in every unit
The color band is a broad comparison for the selected vehicle class, not an official efficiency rating.
Trip and annual estimates
Cost at common distances
Annual vehicle comparison
CO₂ values are approximate direct tailpipe estimates based on fuel volume. They exclude fuel production, electricity, maintenance and vehicle manufacturing.
Trip fuel and cost formulas
Trip fuel equals distance in kilometres multiplied by L/100 km and divided by 100. Cost equals fuel used multiplied by the price per litre.
Why real consumption changes
Traffic, short cold journeys, speed, tyre pressure, terrain, weather, air conditioning, roof boxes, towing and vehicle load can all change fuel use. Compare results over similar routes and seasons.
Compare vehicles fairly
Use the same distance, price basis and driving conditions. A laboratory rating is not directly comparable with a real-world figure unless both values are adjusted consistently.
Related driving and cost tools
Continue with vehicle efficiency, distance, speed, volume and electricity-cost calculations.
Fuel consumption converter FAQ
How do I convert US MPG to L/100 km?
Divide 235.214583 by US MPG. For example, 30 US MPG is approximately 7.84 L/100 km.
How do I convert Imperial MPG to L/100 km?
Divide 282.480936 by Imperial MPG. Imperial and US gallons are different sizes, so their MPG values are not interchangeable.
Is a lower fuel consumption number better?
For L/100 km and gallons per 100 miles, lower is better. For MPG, km/L and miles/L, higher is better.
How can I measure my car’s real fuel consumption?
Fill the tank, reset the trip meter, drive a representative distance, refill to a similar level and divide the fuel added by the distance driven.
How accurate is the estimated tank range?
It is a planning estimate based on the entered usable tank size and average consumption. Reserve fuel, traffic, weather and driving style can reduce the practical range.
Does the trip planner include refuelling stops?
Yes. It estimates stops from total fuel needed and usable tank capacity, assuming the journey begins with a full tank.
What does the real-world adjustment do?
It increases or decreases the entered consumption before calculating fuel, cost, range and emissions. Use it to model conditions that differ from the published figure.
Are the CO₂ results official emissions values?
No. They are approximate direct tailpipe estimates from fuel volume and generic emission factors. Official testing can use different methods and assumptions.