Oster microwaves come in sizes ranging from 0.7 cubic feet at the smallest to 1.4 cubic feet at the largest, according to Sears Hardware. These sizes refer to the total volume the oven occupies, not the volume contained within the cooking space.
The smallest Oster microwave available is 0.7 cubic feet in volume and has a power output of 700 watts. The interior cooking space has a depth of 11.57 inches, a height of 8.66 inches, and a width of 12.40 inches. The next size larger occupies a volume of 0.9 cubic feet and has 900 watts of cooking power. This model has the interior dimensions of 0.66 inches by 13.57 inches by 12.60 inches.
Intermediate Oster microwaves are 1.1 cubic feet in total volume and provide 1,000 watts of cooking power, adds Sears Hardware. Interior dimensions of these models are usually 9.45 inches by 13.94 inches by 14.09 inches. The largest Oster microwave model occupies a total volume of 1.4 cubic feet. This model provides 1,200 watts of cooking power. The dimensions of the interior cooking space are not listed but the exterior dimensions are a height of 12.24 inches, a width of 21.77 inches and a depth of 19.45 inches.