I've been wondering this for a long time and Google doesn't seem to want to give me the answer.

In the United States, the term "miles per gallon" is most commonly used to express the fuel efficiency of an automobile. Given that "mile" and "gallon" are artifacts of the U.S. customary system of measurement, how would someone in a country that uses the Metric system go about expressing this rate? "Kilometers per liter"? "Meters per U.K. gallon"? "Furlongs per hogshead"?

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    It's "rods to the hogshead" not Furplongs per! Sheesh. Commented Mar 3, 2011 at 15:07
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    The UK finds itself in Nonsense Land here. The problem is that Britain is part metric, part imperial in the way it measures. Most things (including petrol) are sold in metric. So whilst we buy our fuel in litres, we still express our distances in miles. Most people, including car sales offices, still state economy in "miles per (imperial) gallon" or "mpg". But in order to work it out for yourself, based on how much fuel you've bought and how far you have driven, you need to do a conversion from litres to imperial gallons.
    – WS2
    Commented Aug 20, 2017 at 14:15

8 Answers 8


The standard measure is in litres per hundred kilometres.

  • What's the abbreviation for that? "Miles per gallon" is MPG. Commented Mar 3, 2011 at 7:01
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    The "abbreviation" is the ordinary scientific expression of the term: <quantity>l/100km. Once you slip into the metric world, you tend to get away from purely alphabetic abbreviations. In the US, you might drive at "60 mph"; in Canada, you would drive at "100 km/h" (but you'd pronounce it "clicks").
    – bye
    Commented Mar 3, 2011 at 8:07
  • Although here in supposedly metric Canada, I still hear "Miles per Gallon" or MPG more often than anything else. What's the word from the UK, OZ, and other English peaking countries?
    – user597
    Commented Mar 3, 2011 at 14:49
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    FYI, the General Conference on Weights and Measures in 1979 adopted the additional symbol L for "liter" to avoid any confusion with the numeral 1. This has become the preferred symbol in North America.
    – ghoppe
    Commented Mar 3, 2011 at 18:35
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    @ShreevatsaR: Note that later in that same Wikipedia article, it mentions that "fuel economy" (distance per volume) and "fuel consumption" (volume per distance) are both expressions of "fuel efficiency".
    – John Y
    Commented Jan 28, 2012 at 2:01

From Wikipedia's page on fuel efficiency:

In the context of transport, fuel economy is the energy efficiency of a particular vehicle, and is given as a ratio of distance travelled per unit of fuel consumed. Fuel economy is expressed in miles per gallon (mpg) in the USA and usually also in the UK—there is sometimes confusion as the imperial gallon is 20% larger then the US gallon so that mpg values are not directly comparable. In countries using the metric system fuel economy is stated in kilometres per litre (km/L) in the Netherlands, Denmark and in several Latin American or Asian countries such as India, Japan, South Korea1, or as the reciprocal ratio, "fuel consumption" in liters per 100 kilometers (L/100 km) in much of Europe, Canada, New Zealand and Australia. Litres per mil are used in Norway and Sweden.

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    litres per mil (Norway/Sweden) - Of note is that a mil is a "Scandinavian mile" ~ 10 km. Commented Mar 3, 2011 at 6:55
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    @amphetamachine: Actually, one 'mil' ("Scandinavian mile") is exactly 10 km.
    – Guffa
    Commented Mar 3, 2011 at 8:37
  • @Guffa amphetamachine ... except in Denmark where 1 mil=7.5 km - but it is not used anymore
    – Stefan
    Commented Aug 20, 2017 at 14:20

Its kilometers per liter. Like 40km average that means in a liter vehicle has ability to run 40 km. (Indian measurement)

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    km/l is the standard measure in Denmark, too. Commented Mar 3, 2011 at 12:02

Here in Germany, it's measured in how many litres of fuel you need to drive 100km (presumably in a particular fashion and with a particular load).

I know that Volkswagen were very proud about 10 years ago when they claimed that the production version of the VW Lupo was the first "3L car" – i.e., used 3L (or less) to go 100 km.


In my country of Iran, it is expressed in L/100km. However, colloquially, people just say the number without the L/100km part. For instance, you would hear people saying something like: "This car burns 5 on highway and 8 in city."


In the UK we use miles per gallon (m.p.g.), but bear in mind that while our miles are the same as American ones, our gallons are bigger.

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    We're in the absurd situation of buying our fuel in litres, but measuring its consumption in m.p.g., because no UK government has had the courage to pursue wholeheartedly the complete adoption of metric measurements. Commented Mar 5, 2012 at 11:54

Once when visiting Canada, I saw a TV commercial for a car, advertising its fuel efficiency in miles per (imperial) gallon. This surprised me, because Canada is (for the most part) a metric country: maps, road signs, and odometers give distance in kilometers, and fuel is sold by the liter!

  • Yes; fuel is sold in litres in Canada, but people commonly refer to miles per gallon. I've never heard anyone talk about litres per hundred kilometres or anything to that effect. Likewise, I find that nobody here measures their height in centimetres; it's all feet and inches. A curious holdover, perhaps?
    – user22138
    Commented Jul 19, 2013 at 19:05
  • @user22138 Nor their weight in kilograms. I've taken it on as a personal challenge to express my height in cm and my weight in kg, to get with the program. A couple more generations and we might actually get to where the are in science fiction, regarding metric. Commented May 9, 2015 at 4:59

So far as I'm aware, Canada uses both miles per gallon and liters per hundred kilometers. The UK is the same as the US in using miles per gallon, even though they primarily buy and sell fuel in liters. Canada, the UK and New Wales are weird in that they're hybrid imperial and metric. The English-speaking countries that are the most thoroughly metric are New Zealand and Australia

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