You've found a beautiful bra and knickers set you adore. There's only one problem, your size isn't available. Fret not, because you still might be able to get it in your "Sister Size."
Your "Sister Size" is the other two or even three size options you have. It's a simple, yet sometime confusing size trick. For example, in my case, my true or primary size is 34H. My two Sister Sizes are 36G or 32I. And if I really want to push the button, I might try my third, 38F.
How is this possible? There is no etched in stone size, because all women are different. Sister Sizing looks at the breast volume and band size. Not all "D" cups have the same volume. If you've been wearing a 32D, and suddenly your band begins to feel tight and you go to a 34D, you just did more harm than good.
What you should have done was increased the band to 34 and decreased the cup to C. The reason for such an odd change...volume. A large band means a larger cup...more volume. All "D" cups aren't the same. Think about. Your best friend is a 30G and you're a 34G, however, your breasts are considerably larger. Your "G" breast volume far outweighs hers "G" volume.
So when shopping for a bra, if your True or Primary size isn't available, look for your Sister Size. To do this, simply increase the band and decrease the cup. Or decrease the band and increase the cup.
Example:
| True Size | Increased Band Size | Decreased Band Size |
| 32E | 34D | 30F |
| 34D | 36C | 32E |
| 36F | 38E | 34G |
| 38G | 40F | 36H |
You'll discover this secret formula will make your bra shopping experience a lot easier.