A dishwasher can certainly add to your electric bill, but it all depends on how often you use it. If you only run the dishwasher once or twice a week, your increase in electric costs will be minimal. However, if you find yourself running the dishwasher multiple times a day, you will see a significant jump in your electric bill. In general, dishwashers are one of the more energy-efficient appliances in the home, so as long as you're not overusing them, they shouldn't make too much of an impact on your monthly expenses.