An average full/queen size comforter can range from 84 inches to 90 inches wide and 90 inches to 95 inches long, depending on the manufacturer. There would be approximately a twenty-five inch or longer overhang to each side of the twin XL mattress; remember to factor in the depth of the mattress when figuring. There is no problem about the mattress head or foot overhang since the pillows will take up any excess, which is minimum.
If you do not want any noticeable side overhang from the comforter, get the full/queen size and fold it down the middle, using the smaller width to give you the cover design you want.
ADD'L...
If the comforter is part of a set which includes sheets, here is an inexpensive quick fix to hold an oversized fitted sheet smooth and in place. Below are some of the names for this product. The Amazon link is included as an example only; big box stores also carry the item.
Sheet Fasteners
Sheet Garters
Sheet Grippers
Sheet Holders
Sheet Straps
Sheet Suspenders
http://www.amazon.com/Grippers-Garters-B...
If the bed is a twin, there's going to be a LOT of overhang on the sides with a full. You could always do some folding/pinning to adjust, though. Good luck!
If the bedding is too big, it will just hang off the ends a little bit. It shouldn't be too much of a problem.
So my favorite bedding at urban outfitters went out of stock in twin xl and queen/full today it came back in the queen/full. Do you think if I order the queen/ full it will be too big for my college bed that's twin xl? The beds are up really high
Thanks so much!
