The majority of retailers, whether they are traditional bricks and mortar high street retailers or online retail websites, will quote their swimwear and beachwear sizes in standard dress size terms, so for the most part, when you are buying beachwear and swimwear, you shouldn't have a problem finding the size for you. However, you might find that some swimwear retailers will quote specific cup sizes and back sizes. This is great because it means you can mix and match bikini tops and bottoms for example, so that you get the perfect fit to enable you to look your best on the beach. One of the pre-requisites though is that you know how to measure yourself.

So, here is a simple two step process for accurate measurement of your bra band size and your bra cup size, for the perfect fitting swimwear.

First Step - Measuring Your Back / Bra Band
The first thing you need to do is get your tape measure and measure under your breast around your rib cage. Make sure the tape measure isn't twisted and make sure it is at the same height all the way around your back. It may be useful to do this in front of a mirror to be sure. Also, make sure that as you measure, the tape isn't too loose or too tight. It shouldn't squeeze, rather it should just sit nice and comfortably around your body. Once, you have this measurement, write it down and add five inches to it. So, if you measured yourself at 31 inches then add five inches to give you 36. So, that's your bra band size - 36.

You may find that you end up with a measurement that is in between normal bra sizes, so instead of 36 you may end up with a 35. In this case, go for the 36 to start with and try it on at home. If it's too big, then you will need the 34. The main thing is to go with what is comfortable but also what looks like it fits nicely in the mirror without squeezing you.

Second Step - Measuring Your Bikini Cup Size
So, the next thing you need to do is work out the cup size of your bra, and therefore your bikini top. To do this, take your tape measure again and this time measure around the fullest part of your breast. As before, make sure that the tape isn't twisted and make sure that it is at the same height all around your body. Again, it may be useful to do this in the mirror. The same rule applies as before. The tape should sit nice and comfortably around your body, it shouldn't squeeze but it also shouldn't be too loose so that it slips.

Now, go back to your bra band measurement and subtract it from the measurement you just took around your breast. The result will be your cup size and the conversion from inches to cup size letters goes as follows:

Less than 1" difference and you will be wanting an AA cup
1" difference - A Cup
2" difference - B Cup
3" difference - C Cup
4" difference - D Cup
5" difference - DD Cup
6" difference - E Cup
7" difference - F Cup

So, taking our example above where we ended up with a band size of 36 inches, if our bust measurement was 39 inches, that's a difference of 3 inches, leaving us knowing that we need a 36C bra size. Simple.

One of the things that you should know is that women very rarely change their bra size even though their body shape and size may have changed over time. Most just stick to what they know. You should measure yourself every time you are thinking of buying a new bra and especially when you buy a new bikini, as lets face it, the bikini will be on public show and you want to look your best, so it is really important to make sure your bikini top fits perfectly.