How do I convert MPG to litres per 100 km?

Divide 235.215 by the US MPG figure (or 282.481 by UK MPG). For example, 30 mpg (US) is 7.84 L/100 km, and 30 mpg (UK) is 9.42 L/100 km.

Why are US and UK MPG different?

The gallons differ. A US gallon is 3.785 litres and an imperial (UK) gallon is 4.546 litres, so the same car scores about 20% more miles per gallon in UK figures.

Is a lower L/100km better?

Yes. L/100 km measures fuel used per distance, so 5 L/100 km is more economical than 8. MPG and km/L measure distance per fuel, so for those a higher number is better.

Fuel Economy

Miles per gallon, km per litre and litres per 100 km.

About Fuel Economy

Convert fuel economy between US and UK miles per gallon, kilometres per litre and litres per 100 km. Enter one value and the other three are shown at once.

How to use

Type a value and pick its unit. The default is 20 miles per gallon (US).
The other three units update as you type; each row has its own Copy button, and Copy on the panel copies the whole table.
Results are rounded to eight decimal places and formatted for your locale.

Conversion factors

Values convert through kilometres per litre:

Unit	km/L
mile per US gallon	0.425143707
mile per UK (imperial) gallon	0.35400619
litres per 100 km	100 / value

Litres per 100 km is an inverse measure: a lower number means better economy, so it is computed as 100 divided by km/L rather than multiplied by a factor. The value must be greater than zero and below 1,000,000.

Example

20 mpg (US) → 24.01899848 mpg (UK) · 8.50287414 km/L · 11.76072918 L/100 km

Privacy

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Frequently asked questions

How do I convert MPG to litres per 100 km?: Divide 235.215 by the US MPG figure (or 282.481 by UK MPG). For example, 30 mpg (US) is 7.84 L/100 km, and 30 mpg (UK) is 9.42 L/100 km.
Why are US and UK MPG different?: The gallons differ. A US gallon is 3.785 litres and an imperial (UK) gallon is 4.546 litres, so the same car scores about 20% more miles per gallon in UK figures.
Is a lower L/100km better?: Yes. L/100 km measures fuel used per distance, so 5 L/100 km is more economical than 8. MPG and km/L measure distance per fuel, so for those a higher number is better.

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