The Best Hamilton Seaside Microwaves On The Market By User Opinions Countertop models are listed in dimension classes according to the producer's claimed inside volume. Compact fashions are 0.5 to 0.9 cubic toes, mid-sized fashions are 1.0 to 1.2 cubic ft, and huge fashions are 1.3 to 2.2 cubic feet. Over-the-range fashions mount instantly over a regular 30-inch range and act each as a microwave and as an exhaust fan. I chose this microwave as a outcome of price and dimension. It actually was somewhat larger, more highly effective than what I was used to and I am glad I did.