MEASUREMENT & METHODS

Litres per 100 km (L/100 km): fuel economy unit guide

Understand litres per 100 km (L/100 km) for fuel economy. Check base-unit equivalents, examples, comparison tables and source conventions.

What is being measured?

Fuel consumption is fuel volume per distance, while economy is distance per fuel volume. The relationship between them is reciprocal and the gallon convention matters.

Fuel consumption and economy are reciprocal. US and imperial gallons differ; inputs must be positive.

Meaning of L/100 km

Litres per 100 km uses the symbol L/100 km in this library and measures fuel economy. Under the stated reference convention, 1 L/100 km = approximately 1 L/100 km. This equivalence changes how a known value is written. It does not increase measurement accuracy or establish whether a measurement is appropriate to a real application.

Conversion method

Multiply the value by the source factor (1), then divide by the target factor (1). The factor ratio expresses the same fuel economy measurement in the other unit.

Worked example

For a known value of 10 L/100 km, the reference conversion gives 10 L/100 km. Converting that result back gives approximately 10 L/100 km. This reverse check helps catch a reversed factor, but matching round-trip arithmetic alone does not independently verify a source definition.

Common reference values

Input (L/100 km)Reference equivalent (L/100 km)
11
55
1010
2525
5050
100100

Compare one L/100 km with other units

Target unitEquivalent of 1 L/100 kmDefinition guide
Miles per US gallon (US mpg)235.214583333Read definition
kilometers per liter (km/L)100Read definition
miles per liter (mi/L)62.1371192237Read definition
uk mpg (imp mpg)282.480936332Read definition

Precision and common mistakes

  • Keep the source and target quantity consistent. A matching symbol is not enough to establish a compatible definition.
  • Record the original measurement precision. Showing twelve significant digits in a table does not make a rounded input more precise.
  • Check symbol capitalization, prefixes and any regional convention in the source. Use the displayed unit definition rather than a similarly named unit.
  • Factors involving repeating fractions or π use finite numerical precision. Round the final answer to the precision justified by your input.

Use a working converter

Source and verification scope

Examples and tables are computed from the versioned unit definitions used by the linked converters. The source access dates appear below. Computandum is independent of the cited organizations; a citation does not mean that a publisher endorses this page or an actual project.

Sources

Read the calculation and sourcing methodology →