If you're shopping for a new dishwasher, one of the first things you'll need to know is how big the appliance is. Dishwashers come in standard sizes, but the dimensions can vary slightly from model to model. The average dishwasher is about 24 inches wide, 34 inches tall and 25 inches deep. However, it's important to check the specific measurements of the dishwasher you're interested in before making your purchase. Otherwise, you might end up with an appliance that doesn't fit in your kitchen!