Understanding Bra Cup Sizes: The Ultimate Measurement Guide
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The Science Behind Cup Sizes
Cup sizes measure the volume difference between bust and underbust measurements, represented alphabetically from AA to N+. Each letter corresponds to specific measurement ranges:
Example: 34B = 34" band + 2" cup difference
International Cup Size Conversion
| Difference (inches) | US | UK | EU | AU |
|---|---|---|---|---|
| 0-1 | AA | AA | AA | AA |
| 1-2 | A | A | A | A |
| 2-3 | B | B | B | B |
| 3-4 | C | C | C | C |
| 4-5 | D | D | D | D |
| 5-6 | DD | DD | E | DD |
*Measurements may vary by 0.5" across brands
Professional Measurement Technique
Step 1: Band Measurement
- Use non-stretch measuring tape
- Measure underbust on exhalation
- Add 4-5 inches for even numbers
Step 2: Bust Measurement
- Measure at nipple level
- Keep tape parallel to floor
- Take three measurements (standing/leaning/lying)
Cup Size Fit Indicators
✓ Good Fit Signs
- No breast spillage
- Center gore lies flat
- Straps don't slip
✗ Poor Fit Signs
- Cup wrinkling
- Band rides up
- Underwire poking
Cup Size vs Breast Volume
| Cup Size | Approx. Volume (ml) | Weight (per breast) |
|---|---|---|
| A | 250-300 | 0.5lb |
| B | 300-400 | 0.7lb |
| C | 400-500 | 0.9lb |
| D | 500-700 | 1.1lb |
Unique Body Considerations
- 🔸 Asymmetric breasts: Fit larger side
- 🔸 Post-surgery: Wait 6 months
- 🔸 Athletic builds: Wider band needed
- 🔸 Nursing bras: +1 cup size
