13 kilometers in millimeters

Conversion formula
How to convert 13 kilometers to millimeters?

We know (by definition) that: $1\mathrm{km}=1000000\mathrm{mm}$

We can set up a proportion to solve for the number of millimeters.

Now, we cross multiply to solve for our unknown $x$:

Conclusion: 13 ⁢ km = 13000000 ⁢ mm

Conversion in the opposite direction

The inverse of the conversion factor is that 1 millimeter is equal to 7.69230769230769e-08 times 13 kilometers.

It can also be expressed as: 13 kilometers is equal to $\frac{1}{\mathrm{7.69230769230769e-08}}$ millimeters.

Approximation

An approximate numerical result would be: thirteen kilometers is about thirteen million millimeters, or alternatively, a millimeter is about zero times thirteen kilometers.