Bra Size Calculator
Your Bra Size
International Size Conversions
Perfect Fit Tips
- Band Fit: The band should sit level and snug, but not tight. You should be able to fit one finger under the band.
- Cup Fit: Your breast should fill the cup without spillage on top or gaps. No wrinkles in the cup fabric.
- Strap Position: Straps should sit on the back of your shoulders, not sliding off or digging in.
- Underwire Placement: The underwire should follow your natural breast contour underneath your breast tissue.
- Band Size: Band sizes run in 2-inch increments (28, 30, 32, 34, etc.). If between sizes, choose the smaller one.
- Cup Size: Each cup size difference equals 1 inch of bust circumference. Going up a band size also requires going down a cup size to maintain fit.
Size Conversion Chart
| US | UK | EU | FR | IT | Band (cm) |
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About the Bra Size Calculator
The Bra Size Calculator helps you find your perfect bra size using your body measurements. Getting the correct size is essential for comfort, support, and proper fit. Many women wear the wrong size without realizing it!
How to Measure Correctly
Step 1: Measure Your Underbust
Wear an unpadded bra or no bra. Measure snugly (but not tightly) around your rib cage, directly underneath your bust. Keep the measuring tape parallel to the ground. This measurement gives you your band size.
Step 2: Measure Your Bust
Keep your bra off or wear an unpadded bra. Measure loosely (not compressing) around the fullest part of your bust, usually at nipple level. Keep the tape parallel to the ground and relaxed.
Step 3: Calculate the Difference
The difference between your bust and underbust measurements determines your cup size. Each inch of difference equals one cup size (A, B, C, D, etc.).
Step 4: Round to Nearest Standard Size
Band sizes come in 2-inch increments. If your underbust is 32.5 inches, round to 32 inches. If it's 33 inches, round to 34 inches.
Understanding Cup Sizes
- AA: Less than 0.5 inches difference
- A: 0.5 - 1.5 inches difference
- B: 1.5 - 2.5 inches difference
- C: 2.5 - 3.5 inches difference
- D: 3.5 - 4.5 inches difference
- DD/E: 4.5 - 5.5 inches difference
- DDD/F: 5.5 - 6.5 inches difference
Key Features
- Accurate Calculations: Based on industry-standard bra sizing formulas.
- International Conversions: Get sizes in US, UK, EU, French, and Italian standards.
- Measurement Flexibility: Input in inches or centimeters.
- Fit Guidance: Get tips for ensuring proper fit and comfort.
- Size Chart: See how your size converts across different countries.
- Mobile Friendly: Works perfectly on all devices.
International Sizing Systems
US/Canada Sizing: Uses band sizes (28, 30, 32, etc.) and cup letters (A, B, C, D, etc.). For example: 34C
UK Sizing: Very similar to US sizing with occasional small differences. For example: 34C
EU Sizing: Uses centimeters for band size. Band sizes typically range from 65cm to 100cm. For example: 80B
French Sizing: Uses dress sizes combined with cup letters. For example: 85B corresponds to approximately 34B US.
Italian Sizing: Similar to French sizing with slightly different conversions.
Common Sizing Mistakes
- Wearing the wrong band size: Many people wear bands that are too large, compromising support.
- Wrong cup size perception: Cup size should be proportional to band size. The same cup letter fits differently in 32B vs 36B.
- Not accounting for stretch: Bra bands stretch over time. You may need to go down a band size or up a cup size as the bra ages.
- Ignoring posture: Slouching can affect measurements. Stand straight with shoulders back when measuring.
- Wearing padded bras while measuring: Use an unpadded bra or no bra for accurate measurements.
Why Proper Fit Matters
- Health: Properly fitting bras provide adequate support and reduce back pain.
- Comfort: No straps slipping, no digging wires, no spillage—just comfort all day.
- Appearance: The right size creates a smooth silhouette under clothing.
- Durability: Wearing the correct size extends the life of your bras.
- Confidence: Feeling supported and comfortable boosts confidence.
When to Re-Size
- After pregnancy and breastfeeding
- After significant weight changes
- Every 6-12 months as bra bands stretch
- If your current bra is uncomfortable
- Before purchasing new bras
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Frequently Asked Questions
1. What's the difference between US and UK bra sizing?
US and UK use very similar systems with band sizes in 2-inch increments and cup letters. The main difference is in some cup size conversions at larger sizes. Generally, they're compatible, but always check brand-specific sizing.
2. How do I convert between US and EU sizing?
EU sizing uses centimeters instead of inches. A general rule: multiply your US band size by 2.5 and add 10 to get the EU equivalent. For example: 32 × 2.5 + 10 = 90cm EU. Cup sizes usually match across these systems.
3. Why do I need to know my cup size separately?
Cup size is relative to band size. A C cup in a 32 band is much smaller than a C cup in a 40 band. Cup sizes increase by 1 inch of bust circumference per size.
4. What if my measurements fall between two sizes?
For band size, round to the nearest size. If you're between 32 and 34, try 32 first (tighter band, larger cup) or 34 (roomier band, smaller cup). For cup size, you may need to try both to see what fits better.
5. Do all bra brands use the same sizing?
No! Brands vary in how they cut and fit bras. A 34B in one brand may feel different in another. Always check brand-specific sizing charts and try on when possible.
6. How often should I check my bra size?
We recommend getting re-fitted every 6-12 months, especially after weight changes, pregnancy, or significant life events. Bra bands also stretch over time.
7. Does weight affect bra size?
Yes, significant weight gain or loss can change your bra size. Both band size and cup size may change. If you've gained or lost more than 10-15 pounds, consider getting re-fitted.
8. What's the correct way to put on a bra?
Fasten the bra on the loosest hook first (band stretches over time). Lean forward slightly, scoop your breast tissue from the sides into the cup, then straighten up. Adjust straps so they sit on your shoulders without slipping.
9. How can I tell if my bra fits correctly?
Signs of proper fit: band sits level all around, no spillage over cup, straps don't slip, underwire sits under breast tissue, and you can fit one finger under the band at the back.
10. What does "sister sizing" mean?
Sister sizes are proportionally the same. For example, 32C = 34B = 36A (same cup volume, different band sizes). Sister sizing helps if your usual size is out of stock.
11. Can I wear the same size in different bra styles?
Not necessarily. Different styles (plunge, balconette, full coverage) fit differently. A size that works for one style may not work for another.
12. Is this calculator 100% accurate?
This calculator provides a great starting point based on your measurements and industry-standard formulas. However, due to brand variations and personal preference, trying on bras in person is still recommended.