42 MPG (US) to L/100km
5.6 L/100km
42 mpg = 5.6 L/100km.
L/100km
5.6L/100km
42 mpg = 5.6 L/100km
The short answer
How many L/100km is 42 MPG (US)?
42 mpg = 5.6 L/100km. L/100km = 235.214583 ÷ MPG (US), so the working is 235.214583 ÷ 42 = 5.6.
The working
MPG (US) and L/100km are reciprocals of each other, so the conversion is a division rather than a multiplication — which is why the two scales never line up evenly.
L/100km = 235.214583 ÷ MPG (US) 235.214583 ÷ 42 = 5.6
How much precision do you need?
Each row is the same answer cut at a different number of decimals, with what that choice costs you. Pick the shortest row whose error is smaller than whatever you are measuring with.
| Rounded to | Answer (L/100km) | Off by |
|---|---|---|
| Whole number | 6 | +0.39965 |
| 1 decimal | 5.6 | −0.00035 |
| 2 decimals | 5.60 | −0.00035 |
Round trip: take 5.6 L/100km back the other way and you land on 42.0026 mpg — a drift of 0.0026 mpg. That gap is the rounding, not the conversion.
Frequently asked questions
What is 42 MPG (US) in L/100km?
42 MPG (US) is 5.6 L/100km. L/100km = 235.214583 ÷ MPG (US), so the working is 235.214583 ÷ 42 = 5.6.
How accurate is 5.6 L/100km?
Rounding to 5.6 L/100km and converting straight back gives 42.0026 mpg, a drift of 0.0026 mpg from the 42 you started with. The factor itself is exact; every bit of that difference comes from the rounding, not the conversion.
Nearby values
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MPG to L/100km Converter
Convert US MPG to L/100km — read a car’s economy the way the rest of the world quotes it.
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