Built-in dishwashers come in two standard widths, 18″ wide and 24″ wide.
18” Wide Built-In Dishwashers: These dishwashers are typically used where space is at a premium, or where a large dishwasher is not necessary. 18 inch built-in dishwashers are common in city dwellings, home wet bars, or one-bedroom apartments.
24” Wide Built-In Dishwashers: The 24 inch built-in dishwasher is the most commonly sold size in America. This is the standard size for most homes and is available in virtually any color and style.
30” Wide Built-In Dishwashers: This is a new, larger option. Recently introduced by Dacor, the 30 inch wide dishwasher is available in both stainless steel and custom panel-ready. Dacor is currently the only manufacturer of this size, so it is not yet considered standard.