Conversion in the opposite direction
The inverse of the conversion factor is that 1 kilometer per hour is equal to 0.00450268979882126 times 138 miles per hour.
It can also be expressed as: 138 miles per hour is equal to kilometers per hour.
An approximate numerical result would be: one hundred and thirty-eight miles per hour is about two hundred and twenty-two point zero nine kilometers per hour, or alternatively, a kilometer per hour is about zero times one hundred and thirty-eight miles per hour.
 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.