Get a solid estimate of you or your family's average laundry load size, in terms of weight. First, place your empty laundry basket on a household or bathroom scale and mark its weight. Once the basket is full and you're ready to do laundry, weigh the loaded basket. Subtract the empty basket's weight from the total weight of the basket and laundry and record the result -- this is the weight of your laundry load. Repeat this process a few times over various loads of laundry to get a good idea of the average weight of a load of laundry in your household.
Choose a two-in-one washer with a width of about 23 inches and a drum capacity of 2.11 to 2.44 cubic feet if your average laundry load weighs 8 pounds or less. If your loads weigh 8 to 12 pounds, go with a compact washer that has a width of 24 inches or less and a capacity of 2.5 to 3 cubic feet.
Select a full-size, top-loading washer -- a machine with a width of 27 inches or more and a capacity of 3 to 3.8 cubic feet -- if your average laundry load clocks in at 12 to 16 pounds. At the high end, choose a front-loading washer with the same width and a capacity of 3 to 4.2 cubic feet if your average load of dirty clothes weighs between 12 and 20 pounds.