The website and the box of the product both state that the capacity of the bowl is 21 ounces, but it is barely 16 ounces.  In fact, when I put 16 ounces of liquid inside to measure it, the bowl was not only filled to the line but overflowed the middle section where the blade goes, and liquid was spilling out onto the base.  While a solid, pulverized ingredient may or may not spill out through the center if overfilled, I can say that this will not hold 21 ounces by any stretch of the imagination.