My table has 2 leafs and extends to seat 8 comfortably. It's probably about 105quot; long with 2 leafs. The wide is 3 1/2 feet. I was thinking I should get a 9' x 12' rug. What does an expert think?
That should work just fine.
that sounds about right, though you might want to consider the size of your dining room also, perhaps getting an area rug that is just shy of the walls, yet that compliments not only the table, but the flooring as well.
The rug should extend past the chairs when they are being sat in so that all chair legs are on the rug. Measure the area with the chairs pulled out from a table a bit and get a rug that size or slightly larger. The 9 x 12 probably works. Nothing smaller will.