Room for ChanceWhat it measures and where it is used
Fuel consumption compares fuel volume with distance travelled, while fuel economy reverses the ratio. L/100 km is common in Europe; miles per gallon reflects US and British practice. The two gallon definitions differ, so US mpg and UK mpg must be selected explicitly.
- Classification
- Volume/distance ratio; distance/volume is its reciprocal
- SI unit
- m²
- Dimension
- L²
L: length; M: mass; T: time; Θ: temperature; N: amount of substance. The dimension symbol N is not the unit symbol for newton.
How it works
L/100 km measures fuel used over a distance; km/L and mpg measure distance per fuel volume. They are reciprocals, so lower consumption means higher economy. Values must be positive.
Example
5 L/100 km ≈ 20 km/L
Available units
Reference unit: L/100 km
| Available units | Reference factor |
|---|---|
| L/100 km | x |
| km/L | 100 / x |
| mpg (US) | 235.214583333 / x |
| mpg (UK) | 282.480936332 / x |
Units, history and conventions
The International System of Units (SI) received its name in 1960. Since the 2019 revision, its definitions use fixed values of seven defining constants. SI base and derived quantities should not be confused with the different units used to express them.