I'm guesstimating close to 500 yards....
I keep two drawers, sorted by color, each drawer has apx. 120 yards. The fabric cabinet currently has about 200 yards. The cutting table has 12 drawers, many of which hold fabric for specific projects, so likely totals another 30 yards, and my other cabinet has boxes of "scraps" which total the remainder.
My DH still encourages me to buy more! I'm the one putting the brakes on!