I would ask your longarmer. Different quilters have different requirements and following what you quilter wants will give you the best results and may save you money. You don't want the quilter to have to spend a lot of time just getting the quilt loaded because you skimped.

I know they suggest 4 inches bigger on each side, but I think 3 should be fine. I have done some with less than that. The quilter must be careful to get it in the frame straight. And turned the right way . I made that mistake once and had to piece on a strip of backing to make it work. It was one of my "to be used"quilts, so no harm done. Hope you enjoy having it all finished!

I know that the batting and backing must be larger than the quilt top. This will be my first big quilt - an 84 x 93 quilt for a full size bed. Is three inches on each side enough to bring this to a long arm quilter? I sure hope so! I'm so tired of this quilt.
Thanks, Mary