The 80% Rule: Why Most Women Wear the Wrong Size
Statistics show that up to 80% of women are wearing the wrong bra size. Usually, the band is too large and the cups are too small. Our Pro Bra Size Calculator uses the industry-standard "Underbust and Overbust" method to help you find a starting point for a better fit.
How to Measure Yourself
- The Band (Underbust): Wrap a measuring tape snugly around your ribcage, directly under your breasts. The tape should be level and tight but not digging in.
- The Bust (Overbust): Wrap the tape around the fullest part of your chest. Do not pull the tape tight; it should rest lightly against your skin.
- The Math: Your band size is usually the underbust measurement rounded to the nearest even number. Your cup size is determined by the difference between the bust and the band (1 inch = A, 2 inches = B, 3 inches = C, etc.).
Signs of a Poor Fit
- The Band Rides Up: If the back of your bra is higher than the front, your band is too large. 80% of the support should come from the band, not the straps.
- Spillage (The "Quad-boob"): If your breasts are overflowing the top of the cups, your cup size is too small.
- Gapping: If there is space between your breast and the cup, your cup size is too large or the style is not right for your shape.
- Slipping Straps: If your straps keep falling, you might need a smaller band size or more supportive cups.
Pro-Tip: "Sister Sizes"
If a 34C feels a bit tight in the band but the cups are perfect, you might try a 36B. This is a "sister size," where the cup volume is the same but the band length differs.