Litres per 100 km to MPG

How to use L/100km to MPG Converter

1. 1
   Enter the consumption. The figure from a European spec sheet or trip computer.
2. 2
   Read both mpg figures. US and UK, because they differ by about a fifth.

About converting litres per 100 km to mpg

Litres per hundred kilometres is a consumption measure: it says how much fuel a journey of a fixed length requires. Miles per gallon is an efficiency measure, saying how far a fixed amount of fuel goes. They describe the same thing from opposite ends, so converting between them is a division rather than a multiplication, and the relationship is a curve rather than a line. The consumption form has a real practical advantage, which is why most of the world uses it. It is linear in the quantity you buy, so the difference between nine and eight litres per hundred kilometres is exactly the same fuel saving per kilometre as the difference between six and five. Miles per gallon does not behave that way — a five-mpg improvement at the bottom of the range saves several times more fuel than the same improvement at the top, which makes mpg a misleading basis for comparing two cars unless you convert first. Working out a trip cost is straightforward in the consumption form and awkward in the efficiency one: multiply litres per hundred kilometres by the distance in hundreds, then by the fuel price. The complication that remains is the gallon. British and American gallons differ by about twenty percent, so a single consumption figure produces two different mpg numbers depending on which is meant, and a specification quoting mpg without saying which country it comes from is genuinely ambiguous. Both are shown here for that reason.

Frequently asked questions