Fuel Economy Converter: mpg, L/100km, km/L
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mpg = 235.215 ÷ (L/100km)Orange dots mark where the steps start and end on the curve. The orange stretch of the axis shows the fuel saved by the step your value falls in.
Fuel consumption and fuel economy are inverses: halve one and the other doubles. That is why the line is a curve, and why each equal step in economy saves less fuel than the one before.
Fuel saved by equal steps in economy:
- 10 → 20 mpg 11.8 L/100km
- 20 → 30 mpg 3.92 L/100km
- 30 → 40 mpg 1.96 L/100km
- 40 → 50 mpg 1.18 L/100km
All Results
Quick Reference Table: Liter per 100 km → Mile per gallon (US)
| Value (L/100km) | Result (mpg) |
|---|---|
| 3 L/100km | 78.4049 mpg |
| 4 L/100km | 58.8036 mpg |
| 5 L/100km | 47.0429 mpg |
| 6 L/100km | 39.2024 mpg |
| 7 L/100km | 33.6021 mpg |
| 8 L/100km | 29.4018 mpg |
| 9 L/100km | 26.135 mpg |
| 10 L/100km | 23.5215 mpg |
| 12 L/100km | 19.6012 mpg |
| 15 L/100km | 15.681 mpg |
| 20 L/100km | 11.7607 mpg |
About Fuel Consumption Conversions
Fuel consumption measures how efficiently a vehicle uses fuel. In Europe and most of the world it is given in liters per 100 kilometers (L/100km), where a lower number is better. The United States uses miles per gallon (mpg), where a higher number is better. The US gallon (3.785 L) differs from the Imperial gallon (4.546 L), so US mpg and UK mpg give different numbers for the same vehicle. To convert L/100km to US mpg, divide 235.215 by the L/100km value. A typical modern car uses 5-8 L/100km (30-47 mpg).
Typical Fuel Consumption
In L/100km a lower number is better; in mpg a higher number is better. US and Imperial mpg differ because the gallons do.
| Vehicle | L/100km | mpg | mpg (imp) | km/L |
|---|---|---|---|---|
| Hybrid hatchback | 4 | 58.8 | 70.62 | 25 |
| Small petrol car | 5.5 | 42.77 | 51.36 | 18.18 |
| Family car | 7 | 33.6 | 40.35 | 14.29 |
| Petrol SUV | 9 | 26.13 | 31.39 | 11.11 |
| Sports car | 14 | 16.8 | 20.18 | 7.143 |
| Articulated truck | 30 | 7.84 | 9.416 | 3.333 |
History of fuel consumption figures
Some countries rate cars by the fuel they burn over a distance, others by the distance they cover on a unit of fuel. The two figures move in opposite directions, and that has shaped how drivers judge savings.
- The US Energy Policy and Conservation Act set Corporate Average Fuel Economy (CAFE) standards for new cars, in miles per gallon, starting with model year 1978.
- A directive of the European Economic Community set a common method for measuring the fuel consumption of cars, stated in liters per 100 km.
- Richard Larrick and Jack Soll showed in Science that people misjudge savings stated in miles per gallon (the "MPG illusion") and that gallons per 100 miles lead to better choices.
- The US Environmental Protection Agency and the National Highway Traffic Safety Administration adopted a new fuel economy label that adds gallons per 100 miles next to miles per gallon, required from model year 2013.
Sources:
- Alternative Fuels Data Center (US DOE): Key federal legislation (opens in a new tab)
- EUR-Lex: Council Directive 80/1268/EEC (opens in a new tab)
- Larrick & Soll, "The MPG Illusion", Science 320 (2008) (opens in a new tab)
- Federal Register: Revisions and additions to motor vehicle fuel economy label (2011) (opens in a new tab)
- fueleconomy.gov: Learn more about the fuel economy label (opens in a new tab)