Miles per gallon and kilometers per liter measure distance per fuel volume. Liters per 100 km measures fuel volume per distance, so the relationship is reciprocal.
US and Imperial gallons differ: 3.785411784 L and 4.54609 L respectively. Comparing MPG values without identifying the gallon can give a misleading result.
The formula
km/L = mpg × kilometers per mile ÷ liters per gallon
L/100 km = 100 ÷ (km/L)
L/100 km = 100 ÷ (km/L)
mile- 1.609344 km
US gallon- 3.785411784 L
Imperial gallon- 4.54609 L
How to use this calculator
- Choose the correct gallon convention.
- Convert to kilometers per liter using the unit definitions.
- Take the reciprocal multiplied by 100 when converting to liters per 100 km.
Worked examples
Metric reciprocal
20 km/L corresponds to 100 ÷ 20 = 5 L/100 km.
Frequently asked questions
Which direction means better fuel economy?
More distance per unit of fuel (MPG or km/L), or less fuel per fixed distance (L/100 km).
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