Some women go through life wearing the wrong sized bra, others have to buy new ones throughout different stages of their lives. But how exactly do you work out your bra size? Is it through trial and era, going to the bra store and taking in 10 different sizes to try or is there a more methodical way you can measure your bra size and cup?
You can do it yourself if you want using a calculator like http://www.berlei.com.au/bra-size-calculator/
Or using a table like: http://www.brasnthings.com/Fitting-Room/The-Perfect-Fit/How-to-measure.html, especially if you have an unusual size, or are embarrassed about going to a fitter.
Of course, even once you know your size you need to try on each bra and check its fit. Look for no 'double boobs', a centre panel that sits flat against your body, and a back that doesn't lift up.