Bra Size Calculator

About Bra Size Calculation

Finding the right bra size is essential for comfort, support, and appearance. Our calculator helps you determine your ideal size based on two key measurements: the band size (underbust) and the cup size (difference between bust and underbust).

How to Take Accurate Measurements

1. Underbust Measurement: Measure snugly around your ribcage, directly under your bust. Keep the measuring tape parallel to the floor. This determines your band size.
2. Bust Measurement: Measure loosely around the fullest part of your bust, keeping the tape straight across your back. This helps determine your cup size.

Understanding Band Size

The band provides 80% of a bra's support, so getting this measurement right is crucial:

• In US/UK sizing, your band size is your underbust measurement rounded to the nearest even number, adding 4 inches if the measurement is under 33 inches.
• In EU sizing, your band size is your underbust measurement in centimeters rounded to the nearest 5.

Understanding Cup Size

Cup size represents the difference between your bust and underbust measurements:

• US/UK sizing: Each inch of difference represents one cup size (A=1", B=2", C=3", etc.)
• EU sizing: Cup sizes are calculated from the centimeter difference (AA=10-12cm, A=12-14cm, B=14-16cm, etc.)

Sister Sizes

Sister sizes are alternative sizes with the same cup volume but different band sizes. They can be useful when fine-tuning your fit:

• To find a sister size with a tighter band: Go down one band size and up one cup size (e.g., 36C → 34D)
• To find a sister size with a looser band: Go up one band size and down one cup size (e.g., 36C → 38B)

Signs of a Good Fit

A properly fitting bra should:

• Have a band that fits snugly on the loosest hook when new
• Have cups that fully contain your breast tissue without overflow or gapping
• Have a center gore (the part between the cups) that sits flat against your chest
• Have straps that stay in place without digging into your shoulders