Essentially the question is that of: How do I choose the correct implant to get the look I am wanting? This is the most important question when it comes to breast augmentation. In order to better address this question, we need to establish 2 main points:
First: Implants do not come in "cup" sizes. They either come prefilled (in case of silicone gel implants) with certain volume or unfilled (in case of saline implants) with a range of fill capacity. In either case, the fluid volume is measured in terms of cc's (very much like a can of soda has 355 cc's or ml of fluid). This is important as many patients request for a certain "cup" size. For example, "I am currently a B cup but would like to be full C cup." So what implant should be used to achieve this? Before we answer this question, let us consider another important fact: most women are fully aware of the fact that bra cup sizes vary by the manufacturer, so with one manufacturer, one may fit into a B bra but may require a C bra with a different company make. In other words, there is variability even within "cup" sizes which makes using "cup" size as a measurement even more frought with potential errors.
Second: For most women, they are more interested in achieving a certain "look" rather than a certain "cup" size which I applaud. After all, as long as the new size "looks" good to you - do you really care whether you require a certain cup sized bra? I think most women would agree with this statement. With this in mind, the real conversion that needs to be take place is: once you've identified the "look" you desire, how do you and your surgeon go about picking the right implant to achieve that "look?"
There are many different ways to get a glimpse of the "look" that you are after. Many offices use gel sizers, others use rice bags, etc. They will all work. So once you've decided on a look that you are seeking, we need to choose the implant to give you that look. Now, because the sizer or the rice bag was placed ON TOP OF YOUR BREASTS, as opposed to under the muscle, I think it makes sense to think a LARGER implant than the sizer is needed to achieve the comparable look - after all, the implant needs to expand the muscle and at times, it needs to "fill out" the extra skin envelope of the breast (as is true for most women after pregnancies) before it starts to expand the breast. So the real question is: what is the conversion factor? If you liked the look of a 300cc gel sizer, then depending on how much extra skin you have, I personally add at least 30cc's to saline implants, and 50 cc's to silicone gel implants, thereby filling saline implants to a total volume of 330-340cc or choosing silicone gel implants of 350cc. At times, if you had chosen a sizer of 400cc, then I would fill saline implants up to 450cc or choose 475cc silicone gel implants - meaning the larger the desired look, greater the conversion factor. By the above discussion, you have already noted that silicone gel implants "fit" smaller than saline counterparts and give lesser projection.
I have been very pleased with the above conversion method - more importantly, my patients have been pleased with their outcomes, as they got the look they were seeking. It's not perfect, but comes pretty close.
Hopefully this helps.
