The formula with 1.1 substituted
miles = 1.1 ÷ 1.609344 = 0.684
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 Kilometres to Miles Converter explains where each comes from and gives a longer table.
At a walking pace of 5 km/h, 1.1 km takes about 13 minutes. At an easy running pace of 10 km/h it takes about 7. In metres it is 1,100.
What 1.1 kilometres means in practice
A distance of 1.1 km comes up on fitness trackers that count a short walk to a shop or a station, and it is roughly the length of the Champs-Élysées from the Arc de Triomphe to the Rond-Point. On foot it takes about 13 minutes.