138 millimeters in kilometers

Conversion formula
How to convert 138 millimeters to kilometers?

We know (by definition) that: $1\mathrm{mm}=1e-06\mathrm{km}$

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

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

Conclusion: 138 ⁢ mm = 0.000138 ⁢ km

Conversion in the opposite direction

The inverse of the conversion factor is that 1 kilometer is equal to 7246.3768115942 times 138 millimeters.

It can also be expressed as: 138 millimeters is equal to $\frac{1}{\mathrm{7246.3768115942}}$ kilometers.

Approximation

An approximate numerical result would be: one hundred and thirty-eight millimeters is about zero kilometers, or alternatively, a kilometer is about seven thousand, two hundred and forty-six point three eight times one hundred and thirty-eight millimeters.