The formula with 32 substituted
L/100km = 235.214583 ÷ 32 = 7.35
The constant is an exact definition, not a rounded factor: the mile is 1.609344 km, the US gallon is 3.785411784 litres and the imperial gallon is 4.54609 litres. The MPG to L/100km Converter explains where each comes from and gives a longer table.
The same 32 mpg (US) is 38.43 mpg on the imperial gallon, 7.35 L/100km and 13.60 km/L. If your 32 mpg figure came from a British source it already uses the imperial gallon, and the metric answer is 8.83 L/100km instead.
What 32 mpg (US) means in practice
32 mpg is 7.35 L/100km, a typical combined rating for a mid-size sedan with a four-cylinder engine. It is the sort of number the Honda Accord and Toyota Camry returned before both went hybrid.