How to use this calculator
Convert fuel economy between mpg, km/L, and L/100 km. Enter a value, choose the source unit, and choose the destination unit.
The method
Enter your values in the labeled fields and choose Calculate. The result panel shows the answer and supporting values when useful.
Value: 1, From: mpgUS, To: L100
Select Calculate to evaluate these example values.
Scope and limitations
Fuel-economy conversion uses exact gallon/mile definitions. L/100 km is reciprocal, so zero or negative economy values are rejected.
Common questions
Can I use different units?
Use consistent units unless this page is a unit converter. The result follows the units implied by the inputs.
Are results exact?
Displayed values may be rounded. Keep extra precision for important follow-up calculations.
Methods & verification
Formulas use standard mathematical definitions and fixed unit factors where applicable. See our methodology for numerical conventions, rounding, privacy, and limitations.