Standard-size and oversize dishwashers have a depth of approximately 24 inches while some space-saving dishwashers have depths of 18-24 inches. Space-saver dishwashers with shallower depths include countertop, portable and in-sink models.
Typically, standard under-counter dishwashers fit into rough openings that are 24 inches wide, 24 inches deep and 35 inches high. Oversize dishwashers have the same depth and height but come in widths as wide as 42 inches.
Other space-saver dishwashers with 24 inch depths include compact dishwashers that are installed under the counter and have a width of 18 inches, under sink dishwashers that tend to be more expensive and require a shallow sink and single drawer dishwashers that are installed under the counter but have a height of 16-17 inches.