There are many mainstream US retailers** that will tell you the wrong way of measuring yourself. Many salespeople will tell you to measure your overbust or to add 4 or 5 inches to your underbust measurement. DO NOT LISTEN TO THEM. Here's how to do it the right way.
You should ideally be measuring in front of a mirror so that you can tell whether you are holding the tape straight. You will need a non stretchy tape measure.
- Put on your best fitting, non-padded bra.
- Measure around your rib cage, immediately under your breasts. Keep the tape as straight and horizontal as possible. Exhale. Then measure tightly under your breasts. This is your underbust measurement. If your underbust measurement is an odd number, say 29, you should try both band sizes around this (28 and 30).
- Measure around the fullest point of your breasts. This is your bust measurement.
- Now subtract your band size from your bust measurement. (For example if you measured 29 and were going to start with a 30 band and your bust measurement is 33, then the result would be 3. If you were going to start with a 28 band the result would be 5.)
- Each number is a cup size. The US system goes: A,B,C,D,DD,DDD. The UK system goes A,B,C,D,DD,E,F,FF,G,GG,H,HH,J. The EU system goes A,B,C,D,E,F.
- If you thought you were a 34C, and you come up with something like 32E, don't worry! Everybody has a different size and shape, and we should celebrate it, not deny it. Many people have a distorted idea of what a “normal” size is because most mainstream retailers only offer band sizes 32-38 and cup sizes A-DD.
Once you have figured out your size, remember that it is just a starting point. You may still need to go up or down in the band or cup. You may also find that certain styles or brands of bras are incompatible with your breast shape. You will eventually find your perfect fit!
**Most US mainstream lingerie retailers suck. However, I have found one exception: Nordstrom. Nordstrom is somewhat better than all the other mainstream retailers in this category as they actually carry a good selection of bras in band size 30. They also carry band size 28 but the selection is small and they do not have a wide variety of cup sizes. If you live near a Nordstrom store I recommend going there and trying on some items.