Do you need a cabinet for a dishwasher?

Standard Dishwashers This means that the rough opening in your cabinets must be 24- by 24- by 35-inch. The dishwasher itself may be somewhere around 23 5/8 by 23 5/8 by 34 inches. Some wiggle room is required to get the dishwasher into place and hook it up; a slightly loose fit is better than a tight one.