h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Hmm... according to this, I should be a 28DD?!?! I am actually a 32B, so something must have gone wrong. Perhaps it is just me... I did try a few of the internet calculators too, but lots of them said I was a 32AA or 'too small to bother'. The only one that seemed to work was where I had to put in 3 measurements - under, over and above.

No, you haven't made a mistake. It might surprise you, but 28DD is quite a normal size to be, it's just that most of the shops only cater for a very narrow average range, and don't want to waste money making bras in sizes they think won't sell. Of course, the only reason they won't sell is that 80% of women are wearing the wrong size!
Specialist shops like Bravissimo go up to a K cup, even in 28 back size - and they sell out!

A DD cup is actually about the average cup size, and a 28 back size is about a UK size 8, so if you're a size 8 with an average size bust, then that size is probably about right.

If you still can't get your head round the idea of being a DD cup, then this page might change your mind: http://www.bigbrasizemystery.co.uk/

"You couldn't possibly be a D cup or bigger... Well actually, you could. And if the statistics are to be believed, you probably are."

Figleaves also give excellent fitting advice, they really know their stuff: http://www.figleaves.com/uk/fitting_room.asp?cat=161

I am definitely not a DD cup. I have only had braests for about 2 years, and I am almost certainly one of the smallest in the class. I was first measured as a double A, and I barely need to wear a bra unless I do sports.

It is possible that if you have a relatively wide upper back, the bust measurement might come out misleadingly large. However, the band size is usually accurate. If your underbust measures 28 inches, and you currently wear a 32B, then you should need a 28D.

Here is figleaves.com's bra fitting guide: http://www.figleaves.com/uk/fitting_room.asp?cat=161 They don't use a measurement system, but concentrate on the fit.
If you go to this page: http://www.figleaves.com/uk/fitting_room.asp?cat=161&txt=5806 and enter your current bra size, it tells you what cup size you would need if you were trying a smaller band. For every band size you go down, you need to go up one cup size in order to stay the same volume.

You should also read this page: http://www.ivillage.co.uk/beauty/promotions/articles/0,,628687_694143,00.html
It explains a bit more about band sizes.

I have a sizing problem and you seem to know you're stuff so here's my problem..
I got measured last month and was said to be a 36A. The 36A bra I'm wearing right now has a big gap at the front of the cups, about the size of the width of my thumb around the breasts and a thumb and first finger width at the bottom of the straps. I don't know if this means it is too big or too small, I think from what you said it means too small (I may be wrong). the weird thing is as part of my gym program the breast size is measured to check for inch loss, last month this measured 36 (when I bought the bras) now it measures 38 so is my bra too small even though I am not bulging out of it, am I pushing it away and causing it to bulge at the front?

I'm not sure I follow exactly what you're describing. If the centre of the bra where the cups meet is being pushed away from your body and not lying flat against your sternum, then the cup size is too small and the band size is probably too large also. If this is the case, you would need to try a 34C, which would be one cup size bigger and one band size smaller. Cup sizes are in proportion to the band size, so for every band you drop, you have to increase the cup size in order to remain the same actual volume.

When you mention that you are being measured, is this by the same person each time, and are you definately comparing the same measurements? A lot of bra fitters will measure your underbust (ribcage) and add several inches to it to determine your band size, so the number you are being told is not your actual measurement. Some people will add 2 inches, others as much as 6. It could be that the person who measured you the second time added more inches. Also, you are not clear on which measurements you are talking about. If you have been given a bra size of 36A, this is not the same as a 36" bust measurement. The "band size" refers to the size of your frame, not your bust, so it should be your ribcage measurement, not your bustline. A 36A bra should fit someone with an underbust measurement of around 36 inches, and a bustline of around 37 inches.

If you are trying to monitor weight loss, you should be measured by your trainer at the gym or by a doctor, and make sure they are taking accurate measurements. Above all, write down the actual exact measurements rather than a bra size (for example, 33" ribcage, 37" bust) then you know you are dealing with raw data.

If you want to find out how to tell if your bra fits you properly, and how to change your bra size if it doesn't, I have a bra fitting guide here: http://www.belladonnaeyes.co.uk/bra_fitting_part_01.htm which will explain all of this in more detail.