Fuel Economy Converter

Converts fuel economy between US miles per gallon, imperial miles per gallon, litres per 100 km, and kilometres per litre. Enter a number and a unit, such as "30 mpg", "30 mpg_uk", "8 L/100km", or "12.5 km/L".

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Converts fuel economy between US miles per gallon, imperial miles per gallon, litres per 100 km, and kilometres per litre. Enter a number and a unit, such as "30 mpg", "30 mpg_uk", "8 L/100km", or "12.5 km/L".

US and imperial gallons differ, so the same car reads about 20 percent higher in imperial mpg. Say which you mean with mpg or mpg_uk.

Use cases

  • Comparing a US car's rating with a European one
  • Converting a rental car's L/100km figure into mpg

Examples

Thirty US mpg

30 mpg
{"mpg_us": 30.0, "mpg_uk": 36.0285, "km_l": 12.7543, "l_100km": 7.8405}

FAQ

Is my data sent to a server?

Yes — the conversion runs on the server for this tool.

Why do mpg and L/100km move in opposite directions?

They measure opposite things. Miles per gallon is distance per fuel, so higher is better; litres per 100 km is fuel per distance, so lower is better. The two are reciprocals of each other.

What is the difference between US and imperial mpg?

The gallon. A US gallon is 3.785 litres and an imperial gallon 4.546, so an imperial mpg figure is about 1.2 times the US one for the same car.