Convert MPG (US) to Liters per 100 km
MPG (US) to liters per 100 km is the conversion you need when a car is rated in US miles per gallon but you read fuel economy the metric way. These two run in opposite directions: mpg measures distance per fuel, while L/100km measures fuel per distance. So you divide 235.214583 by the mpg figure — you don't multiply — and a higher mpg gives you a lower L/100km. Both still mean better economy.
Miles per gallon (US) to Liters per 100 km conversion table
| Miles per gallon (US) (mpg (US)) | Liters per 100 km (L/100km) |
|---|---|
| 1 | 235.214583 |
| 2 | 117.607292 |
| 3 | 78.404861 |
| 5 | 47.042917 |
| 10 | 23.521458 |
| 20 | 11.760729 |
| 50 | 4.704292 |
| 100 | 2.352146 |
| 500 | 0.470429 |
| 1,000 | 0.235215 |
The formula
To convert MPG (US) to liters per 100 km, divide 235.214583 by the US mpg figure:
L/100km = 235.214583 ÷ mpg (US)
A worked example
Say a car is rated at 30 mpg in US figures and you want its metric fuel use:
235.214583 ÷ 30 = 7.84 L/100km
So 30 US mpg is about 7.84 L/100km. Notice the higher the mpg, the lower this number drops — both are telling you the same thing: the car sips fuel.
Why it's an approximation
The number 235.214583 is a rounded value, and the result is approximate for two reasons. First, it's built from converting miles to kilometers and US gallons to liters, and those don't divide evenly. Second, this is an inverse relationship, not a straight multiply — you divide 235.214583 by the mpg figure, so the units read "fuel per distance" instead of "distance per fuel." That flip is exactly why a higher mpg turns into a lower L/100km.
When you'll use it
Reading a metric spec sheet or a European car review after being used to US mpg, or comparing two cars where one is quoted in mpg and the other in L/100km. Just remember the numbers move opposite ways — lower L/100km is the better car.
Frequently asked questions
Why do I divide instead of multiply?
Because the two units are inverses. Miles per gallon is distance per unit of fuel; liters per 100 km is fuel per unit of distance. To flip from one to the other you divide 235.214583 by the mpg (US) number rather than multiplying by a factor.
What is 30 US mpg in liters per 100 km?
About 7.84 L/100km. Take 235.214583 and divide it by 30, and you get 7.84. A thirstier car with a lower mpg would land on a higher L/100km number.
Does a lower L/100km mean better or worse economy?
Better. Because L/100km is fuel used per distance, less fuel for the same 100 km is more efficient. So a high mpg and a low L/100km are two ways of describing the same efficient car.