How many ounces of diced onions in a gallon?

There are 128 ounces in a gallon. If you consider that one medium onion typically yields about 1 to 1.5 cups of diced onions, which is approximately 8 to 12 ounces, you can fit about 10 to 16 medium onions in a gallon, depending on the size and how finely they are diced. Thus, a gallon can contain around 128 ounces of diced onions.