Bra Cup Calculator

Finding the right bra size can often feel confusing and frustrating. Many women wear the wrong size without even realizing it, leading to discomfort, poor support, and posture issues. To make this process easier, we’ve created a Bra Cup Size Calculator—a simple online tool that helps you determine your bra cup size quickly and accurately.

Bra Cup Size Calculator

How to Use the Bra Cup Size Calculator

Using this calculator is straightforward and requires just a measuring tape and a few seconds:

  1. Measure Your Band Size (Under Bust):
    • Place the measuring tape snugly around your ribcage, directly under your bust.
    • Record the measurement in centimeters.
  2. Measure Your Bust Size (Full Bust):
    • Wrap the measuring tape around the fullest part of your bust.
    • Make sure the tape is level and not too tight.
    • Record the measurement in centimeters.
  3. Enter Your Measurements:
    • In the calculator, input your band size and bust size into the corresponding fields.
  4. Click "Calculate":
    • The tool will display your bra size in seconds, showing your band measurement along with the calculated cup size.
  5. Reset If Needed:
    • Want to try again with new numbers? Simply press "Reset" to clear the fields and start over.

Example: How the Calculator Works

Let’s go through a practical example:

  • Band Size (Under Bust): 75 cm
  • Bust Size (Full Bust): 89 cm

The difference between bust and band measurements is:

89 cm – 75 cm = 14 cm

According to the calculator’s scale, a 14 cm difference corresponds to a Cup B.

The result will be displayed as:
75 cm / Cup B

This simple method ensures you can determine your bra size without guesswork.

Why Knowing Your Correct Bra Size Matters

Wearing the right bra size isn’t just about comfort—it can also affect your health and confidence. Here’s why accurate sizing is important:

  • Better Support: Prevents strain on shoulders and back.
  • Improved Posture: Keeps your spine aligned and reduces slouching.
  • Comfort & Confidence: No more pinching, slipping straps, or gaps.
  • Enhanced Appearance: Clothes fit better and look smoother.
  • Breast Health: Avoids long-term discomfort and circulation issues.

Additional Tips for Accurate Measurement

  • Always measure yourself without bulky clothing for precise results.
  • Avoid pulling the tape too tightly—measurements should be snug but comfortable.
  • Measure yourself standing straight in front of a mirror.
  • If you’re between sizes, try both options to see which feels best.
  • Re-measure every few months, as body size and shape can change.

FAQs About the Bra Cup Size Calculator

Here are some of the most common questions users have about bra sizing and this tool:

1. What measurements do I need to use the calculator?
You only need your band size (under bust) and bust size (full bust) in centimeters.

2. How do I know if I measured correctly?
The tape should be snug but not tight, and level all the way around your body.

3. What if my bust measurement is smaller than or equal to my band measurement?
That usually indicates incorrect measuring—double-check both values.

4. Does this calculator work for all bra brands?
It provides a general size estimate, but sizing may vary slightly between brands.

5. Can I use inches instead of centimeters?
For the most accurate results, use centimeters. If you have inches, convert them to cm first.

6. What does the "Cup Size" result mean?
It represents the difference between your bust and band measurements, categorized into standard cup letters (A, B, C, etc.).

7. Is this calculator accurate for all body types?
Yes, it works universally, though individual fit may depend on bra brand and style.

8. How often should I check my bra size?
Every 6–12 months, or if you notice changes in your body, weight, or comfort level.

9. Can pregnancy or weight changes affect my bra size?
Yes, significant body changes can alter both band and cup size.

10. What does "Cup AA" mean?
It indicates a smaller bust-to-band difference, typically less than 10 cm.

11. What does "Cup I+" mean?
It means the bust-to-band difference is larger than 30 cm, indicating a fuller cup size.

12. Can this calculator replace a professional fitting?
It provides a reliable estimate, but an in-store fitting may give more personalized results.

13. Do different countries use different bra sizing systems?
Yes, but this calculator uses a standard metric system (cm), which is widely accepted.

14. Why does my bra still feel uncomfortable even if the size matches?
Different bra designs and materials fit differently—try different styles.

15. How do I know if my current bra is the wrong size?
Signs include slipping straps, underwire digging in, band riding up, or gaping cups.

16. Can I use this calculator if I wear sports bras only?
Yes, but note that sports bras often fit more compressively than regular bras.

17. Will this calculator work for teenagers?
Yes, as long as the correct measurements are entered.

18. How do I convert this result into UK, US, or EU sizes?
You can use online conversion charts to match your result with regional sizing systems.

19. What if I fall between two cup sizes?
Try both—comfort and support should guide your choice.

20. Do bra sizes change with age?
They can, due to hormonal changes, weight fluctuations, or natural body development.

Final Thoughts

The Bra Cup Size Calculator is a practical, easy-to-use tool that saves you from the frustration of guessing your bra size. With just two simple measurements, you can instantly know your cup size and improve your comfort, support, and confidence.