Dishwashers 18 vs. 24

Ann Frederick

Pull out a measuring tape in the average kitchen, and you’ll find an undercounter dishwasher that is 24 inches wide. Because this measurement marks the industry standard, it also represents the majority of dishwashers available to buyers. Those with smaller kitchens may need an appliance that fits an 18-inch-wide opening, and they can find a handful of models to fit the bill.

Colors and Features

An 18-inch-wide dishwasher can cost more than a 24-inch model.

Both 18- and 24-inch dishwashers come in black, white and stainless-steel finishes; you’ll even find some models that accept custom panels to make them blend into your cabinetry. If you want a bisque or silver model, you’ll have to select a 24-inch appliance. Many features associated with full-size dishwashers are also found on 18-inch models, including stainless-steel tubs, water filters, fold-down tines, electronic control pads and noise-control technology.

Cycles and Capacity

Buyers get as many as eight or as few as three wash cycles on a 24-inch dishwasher. The tall-tub versions of these appliances can hold up to 16 place settings. A dishwasher measuring 18 inches wide may offer two to seven wash cycles. Manufacturers do not typically provide information about the number of place settings smaller models will hold.


A built-in, 18-inch dishwasher stands about 32 to 32 ½ inches high and 22 1/2 to 24 inches deep. A portable model can measure 38 ½ inches high and 30 inches deep. A 24-inch dishwasher designed for built-in installation usually measures 32 1/2 to 34 inches high and 23 to 25 inches deep. When shopping for a portable 24-inch model, you can expect it to stand 36 3/8 to 37 inches high and 26 1/2 to 27 inches deep.

Energy Use

You’ll spot the bright yellow Energy Star label on both 18-inch and 24-inch dishwashers. This indicates they exceed the government’s minimum standards for energy efficiency. Government data shows an 18-inch model will cost about $26 to $32 a year to operate with an electric water heater and $18 to $23 to run with a gas water heater. If you buy a 24-inch dishwasher, expect to spend $30 to $35 annually to run it with an electric water heater and $23 to $25 with a gas model.


While it can seem counterintuitive, you may have to pay more to get a smaller dishwasher than a larger one. Models in 18-inch widths had manufacturers’ suggested retail prices starting at $599 in March 2011; you could spend as much as $899 to purchase one of these appliances. On the other hand, 24-inch models ranged in price from $279 to $1,349.