US to UK MPG Converter

About this calculator

US and UK "miles per gallon" are not the same unit because the US gallon (3.785 litres) and the imperial gallon (4.546 litres) differ by about 20% — the imperial gallon is larger, so for the same car, the UK mpg figure is always higher than the US mpg figure (roughly US mpg × 1.201 = UK mpg). The metric equivalent, litres per 100 km, sidesteps the ambiguity entirely and is the standard fuel-economy figure across the EU and most of the world outside the US and UK.

Car shoppers comparing a US-market review to a UK-market review of the same model, and auto journalists and importers converting spec sheets between the two markets, rely on this converter to avoid misreading two very different-looking numbers as directly comparable.