639 meters in kilometers

Conversion formula
How to convert 639 meters to kilometers?

We know (by definition) that: $1\mathrm{m}=0.001\mathrm{km}$

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

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

Conclusion: 639 ⁢ m = 0.639 ⁢ km

Conversion in the opposite direction

The inverse of the conversion factor is that 1 kilometer is equal to 1.56494522691706 times 639 meters.

It can also be expressed as: 639 meters is equal to $\frac{1}{\mathrm{1.56494522691706}}$ kilometers.

Approximation

An approximate numerical result would be: six hundred and thirty-nine meters is about zero point six four kilometers, or alternatively, a kilometer is about one point five six times six hundred and thirty-nine meters.