Conversion formula

The conversion factor from millimeters to kilometers is 1.0E-6, which means that 1 millimeter is equal to 1.0E-6 kilometers:

1 mm = 1.0E-6 km

To convert 138 millimeters into kilometers we have to multiply 138 by the conversion factor in order to get the length amount from millimeters to kilometers. We can also form a simple proportion to calculate the result:

1 mm → 1.0E-6 km

138 mm → L_(km)

Solve the above proportion to obtain the length L in kilometers:

L_(km) = 138 mm × 1.0E-6 km

L_(km) = 0.000138 km

The final result is:

138 mm → 0.000138 km

We conclude that 138 millimeters is equivalent to 0.000138 kilometers:

138 millimeters = 0.000138 kilometers

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 kilometer is equal to 7246.3768115942 × 138 millimeters.

Another way is saying that 138 millimeters is equal to 1 ÷ 7246.3768115942 kilometers.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that one hundred thirty-eight millimeters is approximately zero kilometers:

138 mm ≅ 0 km

An alternative is also that one kilometer is approximately seven thousand two hundred forty-six point three seven seven times one hundred thirty-eight millimeters.

Conversion table

millimeters to kilometers chart

For quick reference purposes, below is the conversion table you can use to convert from millimeters to kilometers