The sizes within the black outline are regarded as being the average range, and are the easiest to find in department stores. The blue section is often classed as large or plus sized, and the sizes in the pink box are considered to be small sizes, i.e. junior/starter bras. As the table shows, a huge section of women are not represented by any of these three departments, and consequently most people do not realise that there is a far wider range of sizes in existence, than are made available. Band sizes go from 28 up to at least 56, and cup sizes start at AA and go up to K. Many people who have not been fitted base their estimate of their own size on what is considered to be average, often leading to wearing a band size which is far too big, and a cup size which is too small. The shaded area represents a more realistic estimate of the range of most common sizes.

Some oft-repeated bra myths:

"The average bra size in the UK is a 36C." More bras are sold in 36C than any other size, but this does not make it the true average size by any means. Given that around 80% of women wear the wrong size bra, a survey of the bras we wear is almost useless in determining the average. Research by Bravissimo found that 60% of C cup wearers should be at least a D cup, and more than half of us are wearing a back size which is too big. The actual average size is probably 34DD.

"Most women are around a B-C cup. DD cups = huge. FF cups = fake." In fact, many women are a much bigger cup size than they think because wearing the wrong back size skews the cup size. The average size is probably at least a D, and a woman can be a DD, E or even F cup without looking much bigger than average. People often forget, or are unaware, that cup size is relative - for example, a 28F would be roughly equal to a 36C in volume, and four cup sizes smaller than a 36F.

"A 32 is small, a 38 is big." It's not as simple as that; the band size is only the size of the ribcage. Someone with a 32 band is just as likely to have DD cups (or even E, F, FF etc) as someone who wears a 38.

"No-one with a small band size has big boobs unless they're fake." As mentioned above, there is no reason why someone with a small band size cannot have a large cup size. People's idea of "normal" size often comes from the sizes available in the shops, so it is understandable that many people equate small band sizes with a flat chest, and large cup sizes with a fuller figure because it's often only the pre-teen bras which go smaller than a 32 band size, and only the plus size bras which go bigger than a DD cup.

"A band size 32 is the smallest you can get, so it must be about a size 8." Many people don't realise that if you know where to look, band sizes actually go down to 28, even in larger cup sizes. A band size of 32 is usually closer to a size 12.

"The number of the bra size is the bust measurement." Another myth arising from the confusion of bra sizing, and the changes in bra sizes over the years. In modern bras, the number is the band size, which is determined by the size of your ribcage, not your bust. If your breasts grow, you need to go up a cup size, not a band size. You only need to get a bigger band size if the one you are wearing is too tight to fasten.

"The bra should fasten on the smallest adjustment to allow you room to grow." This only really applies to pregnant women, who will need a bigger band size as their ribcage expands, or younger girls who are still growing. Bras will stretch over time, so if it already fits you on the smallest adjustment, it will quickly become too big. The purpose of the adjustable back is to allow for this stretching.

"To get your bra size, you have to add 4-5 inches to your underbust measurement, then work out your cup size based on your bust measurement. This is your size set in stone." Adding this much to your underbust measurement would mean your bra would ride up your back and offer hardly any support, especially if your breasts are heavy. If you are trying to get an idea of your bra size from your measurements, then you should just round your under-bust measurement to the nearest even number. Quite apart from that, no formula will work for everyone so the right size is the one that fits!

"The shoulder straps support the breasts." Most of the weight of the breasts should be supported by the band around the chest, not the shoulder straps. The bra relies on the tension of this band to support the cups, and this is why it's so important that you wear the correct back size.

"The size that the lady in the shop tells you is always the right one." While it is always a good idea to get fitted, it is also important to bear in mind that some fitters are better than others. Don't always take their word for it - try on a range of sizes to see for yourself and compare with the pointers in this guide. Many shops only stock the "average" sizes, so if you are very slim and/or a large cup size, they may well put you in the smallest band size and largest cup size they have despite it still not fitting. For example, if you should be a 28F, they might put you in a 32DD. It is advisable to go to a shop which stocks a wide range of sizes. Bravissimo and Rigby & Peller are highly recommended for bra fitting.

"If the shoulder straps dig in and your back hurts, it means you have very heavy breasts and there's not much you can do about it short of getting a breast reduction." If you are suffering pain because of a heavy bust, it's probably your bra, not you, that needs to change! A better fitting bra will not dig in to the shoulders as much, and there may not be any need to resort to surgery.

"A certain amount of spillage is ok - that's what push-up bras are meant to look like anyway." Any amount of spillage in any type of bra means the cup size is too small. Even if you have cleavage, there should still be a smooth line at the edge with no "double boob" effect.

"If your bra leaves red marks around your chest, it means the band size is too small." The truth is that any bra will leave a certain amount of red marks, even if it's quite comfortable. If the band is so loose that it leaves no mark on your skin at all, it's probably too big. Think about how many other kinds of clothes leave red marks on you - knicker elastic, the seams of your jeans, waistbands etc but nobody ever says that means they're too small!

"The band is meant to be "comfy" and not too tight." The band of your bra is actually meant to be quite tight. Not so tight that it is painful, of course, but tight enough that it won't move around much.

"If the back and sides of your bra make your flesh bulge, it's too tight." Bulges around the band of your bra are not necessarily a sign that you need a bigger band size. Wearing a smaller band size can actually reduce bulging, as it will be positioned lower on your back.

The band slides about and rides up at the back. The band of the bra should be horizontal all the way round and quite a snug fit. If you pull the shoulder straps upwards, the band should grip your back. If it slides up easily, or if your boobs pop out under the bottom of the bra, the band size is far too big.

You're always having to pull the back of the bra down. This could be a sign that it is riding up and you need a tighter band.

You are able to fasten the bra at the front and easily twist it round. This method of putting a bra on should not normally be possible if you are wearing the right size. If you can comfortably twist the bra around your body after it has been fastened, it's probably too loose.

The band feels roomy and you can easily fasten the hooks on the smallest adjustment, even when brand new. The band of your bra needs to be a snug fit in order to support the cups, and it should fit on the biggest adjustment so that you are able to tighten it when the elastic starts to wear out.

You can stretch the bra out from your chest by more than an inch or so at the front, or a couple of inches at the back. You should be able to run a couple of fingers around inside the band, but if you can stretch the bra out from your chest, it is too loose.

The shoulder straps dig in. This often means the band is too loose, forcing the straps to take the weight.

The top edge of the cups make a double bulge. The cups should make a smooth profile, even in push-up styles. If you are spilling out, even a small amount, try a bigger cup size.

The underwires do not lie flat against your sternum in the middle. This is another sign that the cup size is too small, as the breasts are not being contained within the cups and are forcing the centre of the underwires out from your chest (a look often sported by page 3 girls.) If you want to enhance your cleavage, look for a bra designed for this purpose in the right size.

The underwires sit on or poke into breast tissue at any point. This means they are not fully enclosing the breasts. Don't forget to check the sides of the underwires under the armpits, they should lie flat against your ribs in the same way that the centre lies flat against the sternum, with no bulging or spilling out.

The fabric of the cups is wrinkled and loose or there is a large gap at the top. This means you're not filling them out fully, so you should try a smaller cup size.