Bin racks are available in various sizes, they are compatible with 6, 9, 12, 15, 18, 20, 24, 27, 30, 36, and 42 inch bins. The load capacity per shelf will vary depending on the size and material of the bins you choose, for example, a steel shelf that can hold 6 bins could have a capacity of 1200 pounds or 600 pounds per shelf.