Spools of thread come in different sizes. We did a queen with the bobbin and upper thread in the same color very loosely quilted and we used about 1 1/2 of the 2000 yard spools. To be safe I will buy 2 2000 yard spools to do a queen. I did baby quilts and I just now they were less thread. I use a different color on the top and bottom. We ran out on the queen and had a hard time finding another spool of the same thread. So be safe so you won't be sorry.