How to find your correct bra size

There's a common but completely wrong myth that your bra size can be found by your underbust measurement plus 5" (if that gives an odd number advice varies between 4" and 6"), with cup size given by subtracting the band size from your full bust measurement. For example, if your underbust measures 31", and full bust is 39", according to the advice above you would probably end up being recommended 36C. Buy a 36C bra with those measurements, and you will almost certainly end up with a band one or two sizes too big, and cup size anything up to 5 sizes too small! It is most important that you totally ignore this rubbish if you want a chance of finding a well fitting bra.Band sizes:The truth is that bra sizing is impossible to do reliably measurements alone, although a ballpark figure can be estimated. The above method will give you totally the wrong ballpark, except possibly if you have an unusually conical ribcage or are a man. Your actual band size is usually somewhere around your underbust measurement plus up to 4" in extreme cases, usually 0-2", sometimes even 1" lower.There is some debate over whether the band size depends entirely on the underbust measurement, or the above breasts measurement needs to be taken into account as well. It may depend on the style of bra, some have a narrow band under the breasts, others (particularly for large cup sizes) have a much wider one so it's possible that it is a factor. One fairly relaible looking formula I've seen suggests taking the average between your above and below bust measurements, going for the small band size if you end up between sizes, maybe even subtracting an inch or two from the average if your underbust measurement is below 33". Some sites say you should just use the above bust measurement as your band size, but don't be surprised if the back band then rides up as it will fit above your breasts and not below, and in case your hadn't noticed your breasts are not on your neck!This highlights another myth I've seen, that smaller sizes need to add more inches to the chest measurement than larger to get the band size. The reason for this is simple, it makes sure as many potential customers as possible believe their size is stocked by the shop! It has no correclation to actual sizes at all, anecdotal evidence suggests it's the other way around and that for small band sizes your band size is approximately equal to your chest measurement, and for large sizes only it's plus 3". Maybe in the realm of 50" chests the classic "add 5" becomes true.So you have a bra you think fits well, how do you know if it's correct and if you need to change?Pretty much the only sign of the band being too small is you physically cannot get into the bra. If it's uncomfortably tight it might be too small, or it may just be the alien (to most women!) sensation of wearing a bra which fits. Remember the first time you ever wore a bra? And then your first underwired bra? Did that feel so comfortable and normal you didn't notice it? If you've been wearing that size for more than a few days then it probably is too tight.The easiest way of telling whether the band is too loose is to try on the next size down. If you can easily get into it, then you should have that size instead. More obvious signs are band riding up, being able to fasten it on the loosest hook even when new, chest pains, too much bounce and sometimes difficulty breathing. Some of these are not obviously traceble to a bad bra fit but magically go away when you wear the correct size. Underwires should lie flat against your chest, if there's a gap between the wires and your breastbone then that is a band size problem, not because you're wearing too small a cup size (although that can be a small factor, you'd need to be about 5 cup sizes out before that could be the only reason).The correlation between band size and dress size is not what you'd expect. Band sizes below 32 are hard to find, so that must correlate to dreszs size 6/8, right? Wrong! It's more like size 10/12, maybe even 14 in some cases. If you are size 6/8 you should be looking at 28 band bras. It's really stupid that outerwear for those sizes is well catered for, but not bras, as women are not TARDISs with one size on the outside and a much bigger one on the inside!Cup sizeGenerally, the cup size = full bust minus band size is not a million miles out. This of course depends on having the correct band size, but also depends on chest and breast shape, and how you're holding the tape measure. For UK sizes, the difference corresponds to cup size as follows: