The formula with 1.3 substituted
miles = 1.3 ÷ 1.609344 = 0.808
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, 1.3 km takes about 16 minutes. At an easy running pace of 10 km/h it takes about 8. In metres it is 1,300.
What 1.3 kilometres means in practice
A 1.3 km distance is a common figure on school and commuter walks, sitting just past the 0.8 mile mark. At a brisk pace it takes about 15 minutes; a jogger covers it in 7 to 8. The value is searched for far more than its neighbours, largely by people reading treadmill or watch summaries.