L/100 km to MPG Converter
Convert L/100 km to US MPG for car reviews and manufacturer specs, with a UK (Imperial) MPG reference table to read European efficiency data either way.
Last updated: May 2026
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L/100 km to MPG reference
| L/100 km | MPG (US) | Typical vehicle |
|---|---|---|
| 4 | 58.8 | Efficient hybrid (e.g. Prius) |
| 5 | 47.0 | Economy hatchback |
| 6 | 39.2 | Compact petrol car |
| 7 | 33.6 | Average family car |
| 8 | 29.4 | Mid-size sedan or small SUV |
| 10 | 23.5 | Larger SUV or light truck |
| 12 | 19.6 | Full-size SUV |
| 15 | 15.7 | Heavy truck or performance car |
US MPG vs UK (Imperial) MPG
The two regions do not share a gallon. A US gallon is 3.785 litres, while a UK (Imperial) gallon is 4.546 litres, so the same fuel use produces a noticeably higher number when expressed in the larger Imperial gallon. That is why a European car rated near "40 MPG" in a US review reads higher in a UK review of the identical vehicle: the figure looks lower in the smaller US gallon simply because each US gallon holds less fuel to cover the same distance. The table below converts each L/100 km value to both standards so a single European spec can be read either way.
| L/100 km | US MPG (235.214583 × 1 ÷ L/100 km) | UK MPG (282.481 × 1 ÷ L/100 km) |
|---|---|---|
| 5 | 47.0 | 56.5 |
| 6 | 39.2 | 47.1 |
| 7 | 33.6 | 40.4 |
| 8 | 29.4 | 35.3 |
| 9 | 26.1 | 31.4 |
| 10 | 23.5 | 28.2 |
Reading a European spec sheet as an American buyer
The L/100km-to-MPG direction is most useful when a US buyer is researching a European car: either an import, a review in a European publication, or a manufacturer spec sheet written for the EU market. European fuel economy figures are published in L/100km by regulation (WLTP cycle); those figures do not appear on the US window sticker, which shows MPG under EPA cycles instead. The two cycles also differ in their test procedure, so the converted figure is a cross-market comparison, not a direct equivalence.
The inverse relationship is the most important thing to internalise: a lower L/100km number and a higher MPG number both mean better fuel economy. A car improving from 8 to 6 L/100km (a 25 percent drop in consumption) becomes 29.4 to 39.2 MPG (a 33 percent jump), because the inverse relationship amplifies improvements at lower consumption levels. This asymmetry also explains why small differences in L/100km between efficient cars correspond to large MPG differences that look dramatic in US headlines.
UK buyers face an additional wrinkle: UK MPG uses the larger Imperial gallon (4.546 L versus the US gallon's 3.785 L). The same 6 L/100km car is 39.2 US MPG but 47.1 UK MPG. When comparing a European review to a UK road-test figure, the gallon standard must match or the comparison is meaningless.
Frequently Asked Questions
Why are there two different fuel efficiency metrics?
Europe uses litres per 100 km (how much fuel for a fixed distance). North America uses miles per gallon (how far you go on a fixed amount of fuel). They measure opposite concepts: consumption vs. economy. This converter translates between the two.
How does the formula work?
MPG (US) = 235.214583 ÷ L/100km. The constant accounts for unit conversion (km to miles, litres to gallons). Lower L/100km values mean better economy and convert to higher MPG values. A car using 5 L/100km gets about 47 MPG.
Why isn't this conversion straightforward?
Because the units measure opposite directions. Lower consumption (L/100km) = better economy (higher MPG). A 10% reduction in consumption doesn't equal a 10% increase in MPG, the relationship is inverse. That's why a constant divisor is needed.
When would I use this?
Comparing car specs across regions, reading international automotive forums, or evaluating fuel efficiency in your preferred metric. US buyers see MPG, European buyers see L/100km. This converter bridges that gap instantly.