Microwave Oven Shelf Bracket - Black by Improvements The Microwave Oven Shelf Bracket fits 30"W ranges with a top spill retainer edge up to 7/8" wide. The shelf is 30"W x 18"D, and it sits 15" above the stove top. These are NOT the flimsy brackets you may have seen elsewhere; this textured enameled steel shelf holds up to 80 lbs