MPG (US) to L/100 Km

1 mile per gallon (US) equals 235.2145833 liters per 100 kilometers.

How to convert miles per gallon (US) to liters per 100 kilometers

Converting miles per gallon (US) to liters per 100 kilometers is not a simple multiplication, so use the formula below.

liters per 100 kilometers = 235.2145833 ÷ miles per gallon (US)

Example: 10 miles per gallon (US) = 23.52145833 liters per 100 kilometers.

Miles per gallon rises as a car gets more efficient, while liters per 100 km falls. The conversion between them is a reciprocal (for US mpg: L/100 km = 235.215 ÷ mpg).

About these units

Mile Per Gallon (US) (mpg (US))

US customaryCurrent unit

Miles traveled on one US gallon of fuel. The standard fuel-economy unit in the United States; higher is better.

American fuel economy became a matter of policy in the 1970s. After the 1973 Arab oil embargo, Congress enacted the Corporate Average Fuel Economy rules in 1975, setting a sales-weighted average for each manufacturer's cars and light trucks. Fleet economy had been sliding until 1973, reaching a low of about 13.4 mpg, then rose as fuel costs rose: about 17 mpg in 1978, 22 in 1982, and about 25.4 mpg for the average new vehicle in the 2020 model year. Earlier still, the Mobil Economy Run (1936 to 1968) tested real-world mileage on a coast-to-coast route.

The US gallon is legally 231 cubic inches, or 3.785411784 litres. It descends from the English wine gallon, redefined as 231 cubic inches in 1706 under Queen Anne and adopted as the US standard in 1836. It is about 17 percent smaller than the imperial gallon, so US mpg figures look lower than British ones for the same car. Mpg has a quirk known as the MPG illusion: going from 10 to 20 mpg halves fuel use, but going from 50 to 60 mpg saves far less, even though both are 10 mpg gains. For that reason the EPA label also shows gallons per 100 miles.

1 mile per gallon (US) = 0.4251437074 kilometers per liter (approximately).

Sources: Wikipedia: Fuel economy in automobiles; Wikipedia: Imperial gallon; fueleconomy.gov: Learn more about the gasoline label

Liter Per 100 Kilometers (L/100 km)

Metric (SI)Current unit

Fuel used to travel 100 kilometers. The standard fuel-economy unit in Europe, Canada, Australia and China; lower is better.

Where miles per gallon asks how far you go, litres per 100 km asks how much you burn. Consumption is the reciprocal of economy, so it behaves linearly: if two cars each drive 100 km, the one that uses 8 litres instead of 10 saves exactly 2 litres, whatever the starting point. The sources I found do not name an inventor or date for the unit, but it is the standard in much of Europe, Africa, Australia, New Zealand, Canada and China.

Lower is better, which surprises people used to mpg. The relationship between the two scales is a reciprocal: for US mpg, L/100 km equals 235.215 divided by mpg. The Smart Fortwo cdi at about 3.4 L/100 km works out to roughly 69 mpg (US), while a full-size SUV in the US averages around 16 mpg on the highway, which is about 14.7 L/100 km. The US EPA introduced gallons per 100 miles, which carries the same logic, to counter the MPG illusion and make comparisons fairer.

1 liter per 100 kilometers = 100 kilometers per liter (exactly).

Sources: Wikipedia: Fuel economy in automobiles; fueleconomy.gov: Learn more about the gasoline label

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