There are two (or three) schools of thought on this.
In base 2 (binary) there are 1024 bits in a kilobit, and 1024
kilobits in a megabit. So in that case you would divide by 1024 to
convert kilobit to megabit.
Most often, especially in the media and common use of the
public, you see base 10 (decimal) where 1 megabit = 1000 kilobit.
This is not preferred, but its very common. In that case you would
divide by 1000 to convert kilobit to megabit.