Los Angeles Metropolitan area is the largest in the world in terms of size.?

I have been looking at google earth for days and measured the largest metros in the world. It appears that LA is the largest, with tokyo coming in second. The size and sprawl of LA is unmatched, probably because of the high automobile dependency. I am referring to the whole urban area not just LA. I don't care about city boundaries, just plainly as long as their are man made buildings and structures that aren't separated by empty land. I just want to double check and make sure this is true.