18 decimeters in kilometers
Result
The conversion result is: 18 decimeters is equivalent to 0.0018 kilometers.[1]
Conversion formula
How to convert 18 decimeters to kilometers?
We know (by definition) that: 1 dm = 0.0001 km.
We can set up a proportion to solve for the number of kilometers.
1 dm / 18 dm = 0.0001 km / x km
Now, we cross multiply to solve for our unknown x:
x km = (18 dm / 1 dm) * 0.0001 km → x km = 0.0018000000000000002 km
Conclusion:
18 dm = 0.0018000000000000002 km

Conversion in the opposite direction
The inverse of the conversion factor is that 1 kilometer is equal to 555.555555555556 times 18 decimeters.
It can also be expressed as: 18 decimeters is equal to 1 / 555.555555555556 kilometers.
Approximation
An approximate numerical result would be: eighteen decimeters is about zero kilometers, or alternatively, a kilometer is about five hundred and fifty-five point five five times eighteen decimeters.
Footnotes
[1] 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.