90x108 is the size of batting for a queen size quilt. I would probably do 110x110. The bigger the better, IMO. But I make "lap quilts" big enough to fit a double bed and am making a king for my queen! My husband and I are both blanket hogs. We sleep with separate blankets for now, until I have made the king for our bed. I'm hoping it will be big enough that we can share. :D