Front-load washers often fit more clothes per cycle than top-load models—a standard one with a 3- to 4.5-cubic foot capacity can accommodate around 12 to 16 pounds of laundry at once.

You could play matchmaker when shopping for new laundry machines, but it’s hard to know whether Washer A and Dryer B are a perfect pair. That’s why manufacturers market appliances in sets that ...