You know they say this is true of 70% of women, are you one of them? I didn't think I was until... yesterday. It just so completely blows my mind that I've been wearing the wrong bra size for 7 years or so, so of course you get to read all about it.
Now, I started out one of those tomboy-ish girls that wore sports bras all the time. Yes, I admit it. People used to try and pop my bra strap- haha on you! I still don't get why it's supposed to be painful because even now with "real" bras it doesn't hurt.
Then one day I decided it was time to grow up and get a serious bra. I didn't even know there was a way to measure and estimate your bra size. I thought you just try them on like any other clothes and see which works. I ended up with a bra that seemed ok, but was a bit loose in the cups and shifted around. The underwire gave me bruising, but dumb me, I thought it was just because my breast shape was off from the years of neglect.
A year or two later I finally found out that you could measure your size, and lo and behold, found that my band size was too big. So I got new bras, and wow! So much better, like it was meant to be. Then I went to Asia and didn't know my international bra size so I got fitted there. At the time I thought it was hilarious that I was 2 cup sizes larger than here in the US. When a particular style I wanted only came a cup smaller, the lady even said I could get it, it would just be a bit tighter- I refused. And yet it seemed strange that the bras over there fit so much better. I chalked it up to them knowing how to make bras fit my body better. It seemed like the bras in the US always made the cups too close, but I just ignored it. Then again I was much thinner then so I suppose it didn't have THAT much of a noticeable effect.
Fast forward 5 years and 13 lbs later. I noticed that my bras weren't fitting as well, and there was some undesireable bulging areas, so naturally I thought that I should increase the band size. That didn't work out too well and I just returned to my old size.
Recently, Victoria's Secret is having a semi-annual sale. But they didn't have my usual size in that particular style. So I ordered one a size up for the band, and one a size up for the cup to try out. They're sister sizes, but interestingly enough the one a cup size larger was more comfortable. And it fit. This confused me so much. I went on a hunt again to make sure my size is still the same. No matter how many times I measured with the "add 4 in if.., add 5 inches if..." method, I kept getting the same size. The online calculators have me a whole cup size lower or something. I finally thought to use conversion calculators using my International size.
What I found out was that I'm supposed to wear one cup size up! Determined to get to the bottom of this, I went out and started trying on bras in store. I found that the fit was different for every brand, but yes, I fit the bras one cup size higher.
I still need to try on a couple more to really see, but for now I suggest you check your own. I found one site where the number for the US calculation is the same as my number for the International size conversion. So it seems pretty consistent to me.
http://www.flattering.com/sizing.html (scroll down)
And here are some tips on what to look for to make sure your bra fits right (don't just go by numbers!)
1. Make sure the band sits flat and parallel to the ground in the back. If it curves upwards, your band is too large.
2. You should only be able to pull the band up 2" away from the skin in the back. Any more and the band is probably too large.
3. Breasts should not spill over the cups. If they do, the cups are too small.
4. Underwire should end behind the breast. If ends up on top, then the cup is too small. (This is how I realized that something might be off.
5. Straps should not dig into the shoulders. Look into decreasing band size for increased support.