How to convert 420 kilometers to miles?
We know (by definition) that:
We can set up a proportion to solve for the number of miles.
Now, we cross multiply to solve for our unknown :
Conversion in the opposite direction
The inverse of the conversion factor is that 1 mile is equal to 0.00383177142857143 times 420 kilometers.
It can also be expressed as: 420 kilometers is equal to miles.
An approximate numerical result would be: four hundred and twenty kilometers is about two hundred and sixty point nine eight miles, or alternatively, a mile is about zero times four hundred and twenty kilometers.
 The precision is 15 significant digits (fourteen digits to the right of the decimal point).Results may contain small errors due to the use of floating point arithmetic.