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MPG & fuel economy

Compare L/100 km, km/L and miles per gallon with separate US and UK gallons.

Your numbers

Your result

Litres per 100 km
6.5
MPG (US gallon)36.19
MPG (UK gallon)43.46
Kilometres per litre15.38
Rounded for display. See method below.

How it works

US gallon = 3.785411784 L; UK gallon = 4.54609 L; mile = 1.609344 km. MPG = (100 × litres per gallon ÷ km per mile) ÷ L/100 km.

What to keep in mind

Consumption and economy are reciprocal, so zero is not a valid input. These are unit conversions, not measured vehicle efficiency or electric-vehicle MPGe.

Worked example

Fuel economy value: 6.5; Input unit: L/100 km.

Litres per 100 km: 6.5 · MPG (US gallon): 36.19 · MPG (UK gallon): 43.46 · Kilometres per litre: 15.38.

Common questions

Why do US and UK MPG differ?

An imperial gallon contains more litres than a US gallon, so the same vehicle has a higher UK MPG value.