Quick example
Convert 30 US mpg to L/100 km
Divide the US conversion constant, 235.2145833, by 30 miles per gallon. The result is approximately 7.84048611111 L/100 km, or about 12.7543 kilometers per liter.
Quick reference
Common fuel economy conversions
| Starting value | Equivalent |
|---|---|
| 20 mpg (US) | 11.7607 L/100 km |
| 30 mpg (US) | 7.84049 L/100 km |
| 40 mpg (US) | 5.88036 L/100 km |
| 50 mpg (US) | 4.70429 L/100 km |
| 5 L/100 km | 47.0429 mpg (US) |
| 6 L/100 km | 39.2024 mpg (US) |
| 7 L/100 km | 33.6021 mpg (US) |
| 8 L/100 km | 29.4018 mpg (US) |
Unit definitions
US gallons, Imperial gallons, and metric economy
US mpg
Miles per US gallon uses a gallon of exactly 3.785411784 liters. It is the common fuel-economy unit in the United States.
Imperial mpg
Miles per Imperial gallon uses a gallon of exactly 4.54609 liters. The larger gallon produces a higher mpg number for the same efficiency.
Liters per 100 km
L/100 km measures fuel consumed over 100 kilometers. A lower number means less fuel is used for the same distance.
Kilometers per liter
Km/L measures distance traveled per liter. Like mpg, a higher number means better fuel economy.
Reciprocal scales
Higher mpg, lower L/100 km
Distance-per-volume units and volume-per-distance units move in opposite directions. Doubling mpg halves L/100 km; halving L/100 km doubles mpg. A value of zero cannot be converted because its reciprocal would be infinite, so this tool requires a finite value greater than zero. Displayed results use up to 12 significant digits.
Common questions
Fuel economy conversion FAQ
How do I convert mpg to L/100 km?
For US mpg, divide 235.2145833 by the mpg value. For Imperial mpg, divide 282.4809363 by the mpg value.
What is 30 US mpg in L/100 km?
30 miles per US gallon is approximately 7.84049 liters per 100 kilometers.
What is the difference between US mpg and Imperial mpg?
A US gallon is exactly 3.785411784 liters, while an Imperial gallon is exactly 4.54609 liters. The same vehicle therefore has a higher numerical Imperial mpg value.
What is 5 L/100 km in US mpg?
5 liters per 100 kilometers is approximately 47.0429 miles per US gallon.
Is a higher fuel economy number always better?
Higher is better for mpg and km/L. Lower is better for L/100 km because it measures fuel used over a fixed distance.