I pump out 3 times in office, 10am, 2pm & 6pm, got 3-4oz/time per 20-25mins. total have 10-12oz. I also pump (4oz) in the morning at 6am, as my BB just eat one side. So my 99 could have 16oz to bottle feed 3 meals during daytime. Forturnatly, no formula is needed.