Compare Fuel Economy Across Different Units
A US gallon and an imperial gallon are not the same volume.
Check the gallon definition
A US gallon and an imperial gallon are not the same volume. Two vehicles described simply as mpg may therefore be using different units. Select the exact unit before comparing their displayed figures.
Remember the direction reverses
A larger miles-per-gallon figure means more distance from each gallon. A smaller litres-per-100-kilometres figure means less fuel for the same distance. The conversion is reciprocal rather than a simple fixed multiplier.
Compare like test conditions
A unit conversion cannot make an urban test equivalent to a highway test or account for driving style, load, weather and traffic. Keep the original measurement conditions with the converted figure when discussing a comparison.
Keep trip planning separate
Actual fuel needed for a trip depends on distance and achieved consumption. A converted economy figure is a starting assumption rather than a guarantee of range. Confirm the unit and use a realistic measured value for your own calculation.
Put it into practice
Average Speed Calculator
Calculate average speed from kilometres travelled and elapsed minutes, with km/h, mph and m/s results.
Everyday calculatorsFuel Economy Converter
Convert litres per 100 kilometres, US miles per gallon and imperial miles per gallon.
Everyday calculatorsUnit Converter
Convert length, mass, temperature and duration units, with clear source and destination units beside every result.
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