Thank you for your question.
If done well and you have an adequate breast skin, you can expect to get about a 150-200 cc increase in breast volume on each breast. There is a limit to how much fat can be added and it is difficult to go more in one session. This amounts to about a one cup size increase in many women.
The reason that more cannot be added is because the breast tissue starts to get tight and fat starts to die.
So, when done well, a modest increase in breast volume can be achieved and about 70-80% of the fat lives. If pushed too far and too much fat is injected, fat starts to die and only about 30-50% of the fat will live.
I hope this helps.