Bra Cup Size Calculator
Calculate your bust size to bra size with accurate measurements supporting US, UK, EU, FR, and JP standards
Measure snugly under your bust
Measure around the fullest part while standing straight
Measure around the fullest part while leaning forward 90°
Enter your measurements to calculate bra size
Measuring Steps:
- Wear your best-fitting bra or no bra
- Measure under bust: snug, level around ribcage
- Measure bust standing: loosely around fullest part while standing straight
- Measure bust leaning: around fullest part while leaning forward 90°
- Keep tape measure parallel to ground
- Record measurements to nearest half unit
Measure at the end of exhale for most accurate results
About Our Bra Size Calculator
Our bra size calculator uses your bust and under-bust measurements to determine your perfect bra size across multiple international standards. Whether you're shopping for US, UK, European, French, or Japanese brands, our calculator provides accurate conversions.
The calculator takes into account the differences between regional sizing standards and provides confidence ratings to help you make informed purchasing decisions.
Our Commitment to Accuracy
We understand that finding the right fit can be challenging due to varying standards. Our calculator's logic is based on the European standard EN 13402, which uses the difference between your bust and under-bust measurements to determine cup size. This method provides a consistent and accurate starting point for your search.
For a comprehensive understanding of global sizing, we refer to the International Organization for Standardization (ISO). The key standards, such as the ISO 8559 series (which defines body measurement and size designation), are developed and managed by the official ISO/TC 133 committee on clothing sizing systems.
Professional Measuring Tips
Best Time to Measure
- • Measure in the afternoon when your body is at its largest
- • Avoid measuring during menstruation when breasts may be swollen
- • Take measurements while standing straight
- • Measure at the end of exhale for consistency
Measuring Technique
- • Use a soft measuring tape, not a rigid ruler
- • Keep the tape parallel to the ground
- • Tape should be snug but not tight for under-bust
- • Tape should be loose for bust measurement
International Bra Size Chart (Example)
| US | UK | EU | Band (cm) | Bust (cm) |
|---|---|---|---|---|
| 32A | 32A | 70A | 68 | 81 |
| 34B | 34B | 75B | 73 | 89 |
| 36C | 36C | 80C | 78 | 97 |
| 38D | 38D | 85D | 83 | 105 |
Please Note: This chart is based on data from our `size-charts.json` file and serves as a general reference. Sizes can vary significantly between different brands and styles. We always recommend checking the specific size guide of the brand you are interested in.
Frequently Asked Questions
Q: How often should I measure my bra size?
A: You should measure your bra size every 6-12 months, or whenever you experience significant weight changes, pregnancy, or hormonal changes that might affect your body.
Q: What if my measurements fall between sizes?
A: If you're between sizes, consider your preferred fit. For a snugger fit, choose the smaller size. For more comfort, choose the larger size. Also consider sister sizes (e.g., 34C = 32D = 36B).
Q: Do bra sizes vary between brands?
A: Yes, bra sizes can vary significantly between brands and styles. Our calculator provides a starting point, but it's always best to try on bras when possible or check brand-specific size charts.
Q: What are sister sizes?
A: Sister sizes are different bra sizes that hold the same cup volume. For example, 34C, 32D, and 36B are sister sizes. If one size doesn't fit perfectly, try the sister sizes.
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