How do you measure your cup size? girls only please
fill it with water and see how many ounces it takes
Victoria's Secret does free fittings...
Trial and error! Go to the lingerie store and try away!
Find a paper or cloth tape measure and that is used for clothing and wrap it around your back and put it in the inches side and pull it around front then look at the number
There's a chart and directions on Victoria's Secret website.
go to a department store and start trying them on.
This link will show you ho to do it -- there is a video http://www.herroom.com/bra-fitting-advice,901,30.html
How about using this?http://www.anchorhocking.com/images/product_images/product%20item%20main&thumbs/prep/MeasuringCup32oz55178OL_Main.jpg