Standard wall ovens are available in widths of 24, 27 and 30 inches and heights ranging from 28 to 50 inches. These are the standard sizes.
When choosing a wall oven, consider the size of the oven cabinet opening, as this determines the size of the oven.
Another factor to take into account is the wall oven capacity. An oven space of 2 to 3 cubic feet can accommodate a family of two; 3 to 4 cubic feet can accommodate a family of three or four and 4 cubic feet and more can accommodate a family of four or more.