Where are you viewing them to see them in KB?
When I download pictures to google, it says pictures are 5mb. After I upload to lightroom, and edit, it goes to KB....
is there a way to transfer them to MB?
The flip answer would be, "Divide by 1024," because 1 MB = 1024 KB.
However, you will have to provide more information about how you are outputting the photos, i.e. exporting them from Lightroom. Are you resizing them during export? What are the pixel dimensions of the original and the exported images? Are you exporting them as jpgs? If so, with what compression (Quality setting)?
File size is determined by two things: pixel dimensions and compression (actually also by a third thing, bit depth, but since we seem to be talking about jpgs here, that is irrelevant). Without more specific information your question can't be answered.