Bra Size Calculator

Discover your accurate bra size with our easy-to-use calculator. Input your measurements to find your perfect band and cup size for ultimate comfort and support.

cm
cm
Result
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functions Mathematical Formula

Formula Used

Our Bra Size Calculator uses a simplified method based on common European (EU) sizing conventions.

Band Size = Round(Underbust Measurement / 5) * 5

Cup Difference = Bust Measurement - Underbust Measurement

Cup sizes are then assigned based on this difference:

  • < 10 cm difference: AA
  • 10-12 cm difference: A
  • 12-14 cm difference: B
  • 14-16 cm difference: C
  • 16-18 cm difference: D
  • 18-20 cm difference: E
  • 20-22 cm difference: F
  • and so on...

Why Proper Bra Size Matters

Wearing the correct bra size is crucial for both comfort and health. An ill-fitting bra can lead to a host of problems, including back pain, shoulder grooves, skin irritation, and even poor posture. A well-fitted bra, conversely, provides adequate support, enhances your silhouette, and boosts confidence by ensuring your breasts are comfortably and securely held in place, allowing you to move freely throughout your day without discomfort.

How to Measure Accurately

  • Underbust Measurement: Wrap a measuring tape snugly but not too tightly around your rib cage, directly under your bust. Make sure the tape is parallel to the floor. Exhale completely to get the smallest measurement. This is your band size.
  • Bust Measurement: Wrap the tape measure loosely around the fullest part of your bust (usually at nipple level). Make sure it's not too tight and not crushing your breasts. Take this measurement while wearing a non-padded bra for accuracy.
  • Always measure in centimeters for consistency with this calculator.

Understanding Sizing Systems

Bra sizing isn't universal, with different systems used globally:

  • EU Sizing: Uses centimeters for the band, usually in increments of 5 (e.g., 70, 75, 80). Cup sizes are sequential (A, B, C, D, E, F...). Our calculator provides an EU-style estimate.
  • UK Sizing: Uses inches for the band (e.g., 30, 32, 34). Cup sizes follow a similar pattern but include double letters like DD, FF, GG before single letters resume.
  • US Sizing: Also uses inches for the band. Cup sizes often include triple letters for larger sizes (e.g., DDD, FFF), making conversions tricky.
  • Always check brand-specific size charts, as minor variations are common.

Signs of an Ill-Fitting Bra

Recognizing an ill-fitting bra is the first step to finding a better one:

  • Band Digging In: If the band leaves red marks or feels too tight, it's too small. It should sit horizontally and comfortably.
  • Gapping Cups: If there's space between your breast and the cup, the cup size is too big.
  • Overflowing Cups: If your breast tissue spills over the top or sides of the cups, they are too small.
  • Straps Digging: While straps offer some support, they shouldn't bear the full weight. If they dig in, your band isn't providing enough support.
  • Underwire Poking: The underwire should lie flat against your rib cage, not dig into breast tissue or float away from your body.

Frequently Asked Questions

How accurate is this bra size calculator?

Our calculator provides an estimated bra size based on standard EU measurement differences. It's a great starting point, but individual body shapes and brand-specific sizing can mean slight variations. We recommend trying on bras and adjusting based on fit.

Should I use inches or centimeters for measurement?

This calculator is designed to work with centimeter measurements. For best results, please use a tape measure that provides readings in centimeters for both your underbust and bust measurements.

What if my measurements fall between sizes?

If your measurements are between sizes, it's often best to try both the calculated size and its 'sister sizes'. Sister sizes have the same cup volume but different band and cup letters (e.g., 75B and 70C are sister sizes). Experimenting with nearby sizes can help you find the perfect fit.

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