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Fuel Economy Converter

Result

Calculated result Ready Change any value to calculate instantly.
↗ Conversion

Convert fuel economy values using exact relationships between distance-per-fuel and fuel-per-distance units.

Formula

Fuel economy conversion between US mpg, Imperial mpg, km/L and L/100 km
  • Convert fuel economy values using exact relationships between distance-per-fuel and fuel-per-distance units.
  • The main inputs are Value, From unit, To unit. Enter them in the units and format shown in the calculator.
  • For unit conversions, the calculator applies the conversion relationship shown above and keeps source and target units consistent with the selected options.
  • Changing any input above recalculates the result with the same calculation engine used by this page.

Example: Fuel Economy

Inputs
  • Value: 30
  • From unit: US mpg
  • To unit: L/100 km

300 miles using 10 US gallons gives 30 mpg.

Sample result: Calculating…

Frequently asked questions

What does the Fuel Economy calculate?

Use the same trip distance and fuel consumed; Imperial gallons require a different MPG convention.

Which values should I enter?

Enter Value, From unit, To unit using the units and format shown beside each field.

What formula does this calculator use?

The calculator uses the following relationship: Fuel economy conversion between US mpg, Imperial mpg, km/L and L/100 km.

Why might my result differ from another source?

Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.

Does the result update automatically?

Yes. Changing an input updates the result using the same calculation engine shown on this page.

Page information

Updated: October 6, 2026