We take the cubes out before we start eating/drinking the slushie, they do take up a lot of space. Generally when you use 3 cubes and fill to the line, it makes up a bit less than half the cup of slushie. I did see some people put out negative reviews because of that, but IMO, my DD doesn't need that much anyway, esp when we're using juice, choc milk, other sugary drinks- maybe that's why it doesn't bother me.