Cup Size Calculator | Find Your Bra Cup Size Instantly
Enter your band and bust measurements to instantly calculate your bra cup size. Understand what your cup letter really means and how it's determined.
What Is Bra Cup Size?
Cup size represents the difference between your bust measurement and band measurement. Each letter (A, B, C, etc.) represents approximately 1 inch of difference. This simple calculation determines your cup size in every sizing system worldwide.
快速罩杯计算器
Enter your measurements in inches below
您的罩杯尺码
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罩杯尺码对照表
| Cup | Difference (Bust - Band) | 说明 |
|---|---|---|
| A | 1 inch | Small bust. 1 inch difference between bust and band. |
| B | 2 inch | Small to medium bust. 2 inch difference between bust and band. |
| C | 3 inch | Medium bust. 3 inch difference between bust and band. |
| D | 4 inch | Full bust. 4 inch difference between bust and band. |
| DD | 5 inch | Full to large bust. 5 inch difference between bust and band. |
| E | 6 inch | Large bust. 6 inch difference between bust and band. |
| F | 7 inch | Very large bust. 7 inch difference between bust and band. |
| G | 8 inch | Extra large bust. 8 inch difference between bust and band. |
How Cup Size Is Calculated
The calculation is simple: subtract your band measurement from your bust measurement. Each inch of difference corresponds to one cup size letter.
- 测量您的底围尺寸: Wrap a measuring tape snugly around your ribcage, directly under your bust. Round to the nearest whole number.
- 测量您的胸围尺寸: Measure around the fullest part of your bust, keeping the tape parallel to the floor.
- Subtract and match: Bust minus band = cup size difference. 1 inch = A, 2 inches = B, 3 inches = C, and so on.
常见问题
如何计算我的罩杯尺码？
Subtract your band measurement from your bust measurement. The difference in inches determines your cup: 1 inch = A, 2 = B, 3 = C, 4 = D, 5 = DD/E, 6 = DDD/F, 7 = G.
What does my cup size actually mean?
Your cup size represents the volume difference between your bust and ribcage. It's not an absolute size — a 34C and 36C have different cup volumes because the band size changes the proportions.
How do I measure for cup size at home?
You need a soft measuring tape. Measure your band size around your ribcage under your bust (snug) and your bust at the fullest point. The difference between these two numbers gives your cup size.
需要完整的文胸尺码吗？
Use our complete bra size calculator for your exact band + cup combination, sister sizes, and international conversions.
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