Bra Size Calculator - Find Your Perfect Fit
Calculate your accurate bra size using band and bust measurements. Get US, UK, and EU sizes, discover sister sizes, and learn proper fitting techniques with our comprehensive bra size calculator.
Measuring Tips
- • Measure without wearing a bra or wear a non-padded bra
- • Stand straight with arms at your sides
- • Breathe normally - don't hold your breath
- • Have someone help you for more accurate measurements
- • Measure multiple times and use the average
Common Sizing Mistakes
- • Wearing a bra while measuring (adds 2-4 inches)
- • Measuring over clothing instead of bare skin
- • Not keeping tape measure level around body
- • Pulling tape too tight or leaving it too loose
- • Rounding up band size (always round to nearest even)
When to Re-Measure
- • Every 6-12 months as bodies naturally change
- • After weight change of 10+ pounds
- • During/after pregnancy and breastfeeding
- • When experiencing discomfort with current bras
- • After starting or stopping hormonal medications
Quick Fit Check
Signs of a Good Fit
Common Fit Issues
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Did You Know? Studies show that up to 80% of women wear the wrong bra size, leading to discomfort, poor posture, and inadequate support. Regular measuring and proper fitting can significantly improve comfort and appearance.
Understanding Bra Sizing
Bra sizing combines two measurements: the band size (the number) and the cup size (the letter). The band provides 80% of the support, while the cups shape and contain breast tissue. Understanding how these components work together is essential for finding your perfect fit. Modern bra sizing has evolved from the original 1930s system, with today's bras featuring advanced materials and construction techniques. Learn about proper measuring techniques and explore different calculation methods.
📏 Band Size
🔤 Cup Size
👯 Sister Sizes
🌍 Regional Differences
Complete Measuring Guide
Accurate measurements are the foundation of finding your perfect bra size. Take measurements without wearing a bra or while wearing a non-padded bra for the most accurate results. It's best to have someone help you to ensure the measuring tape stays level and properly positioned. Measure multiple times and use the average for best results. Understanding how measurements translate to sizes will help you shop confidently.
Band/Underbust Measurement: Measure around your ribcage directly under your bust. Keep the tape snug but not tight - you should be able to fit two fingers under it. The tape should be parallel to the floor all around your body.
Bust/Overbust Measurement: Measure around the fullest part of your bust, typically at nipple level. Keep the tape parallel to the floor but don't pull it tight - it should glide smoothly over your skin without compressing tissue.
Posture Matters: Stand straight with arms at your sides, feet shoulder-width apart. Breathe normally - don't hold your breath or suck in your stomach. Take measurements at the end of a normal exhale for consistency.
Time of Day: Measure in the morning when possible, as body measurements can fluctuate throughout the day due to water retention and activity. Avoid measuring during your menstrual period when breasts may be swollen.
Recording Measurements: Write down measurements immediately and note the date. Keep a record to track changes over time and to reference when shopping for bras online or in different countries.
💡 Measurement Tips by Body Type
Size Calculation Methods
There are several methods for calculating bra size, each with its own merits. The traditional "+4" method adds 4 inches to the underbust measurement, while modern methods use the actual measurement or add 0-2 inches. Our calculator uses an adaptive approach that considers both methods and provides the most likely fit. Understanding these different systems helps when shopping across brands and countries.
📐 Modern Method
- Round underbust to nearest even number
- Add 0-2 inches for comfort if needed
- More accurate for modern elastic materials
- Preferred by professional fitters
- Subtract band from bust measurement
- Each inch difference = one cup size
- A=1", B=2", C=3", D=4", DD=5"
📏 Traditional Method
- Add 4" if underbust is even
- Add 5" if underbust is odd
- Based on vintage bra construction
- May result in looser bands
- Still used by some US brands
- Common in department stores
- May need sister sizing adjustment
International Size Conversions
Bra sizing varies significantly between countries and regions. Understanding these differences is essential for international shopping and finding the right fit across different brands. Each system has its own measurement standards and cup progression, making conversion charts invaluable. Always check brand-specific sizing guides as even within countries, sizing can vary. Learn about brand-specific variations for more accurate shopping.
| US Size | UK Size | EU Size | FR Size | IT Size | AU Size |
|---|---|---|---|---|---|
| 30A | 30A | 65A | 80A | 1A | 8A |
| 32B | 32B | 70B | 85B | 2B | 10B |
| 34C | 34C | 75C | 90C | 3C | 12C |
| 36D | 36D | 80D | 95D | 4D | 14D |
| 38DD | 38DD | 85E | 100E | 5E | 16DD |
Understanding Sister Sizes
Sister sizes are bra sizes that have different band and cup letter combinations but the same cup volume. This concept is crucial for finding the perfect fit when your calculated size isn't available or doesn't feel quite right. Understanding sister sizing helps you navigate size variations between brands and find alternatives that maintain the same cup volume while adjusting band fit. This knowledge is particularly useful for online shopping and finding sales.
👯 Sister Size Chart
Complete Fit Guide
A properly fitted bra should feel comfortable from the moment you put it on - no breaking-in period required. The band provides the majority of support, not the straps. Understanding what proper fit looks and feels like helps you identify when adjustments are needed. Regular fit checks ensure continued comfort as your body changes. Learn to identify common fit problems and their solutions.
✅ Signs of Good Fit
- • Band is level and snug on loosest hook
- • Cups fully contain breast tissue smoothly
- • Center gore lies flat against sternum
- • Straps stay in place without digging
- • No gaps or overflow in cups
- • Underwire follows breast root
- • Comfortable all-day wear
❌ Signs of Poor Fit
- • Band rides up your back
- • Straps carry all the weight
- • Quadboob or spillage effect
- • Cups gap or wrinkle
- • Center gore floats away from chest
- • Underwire pokes or sits on tissue
- • Constant readjustment needed
Common Fit Problems & Solutions
Most bra fit issues can be resolved by adjusting size or style. Understanding the root cause of discomfort helps you make informed adjustments. Sometimes the issue isn't size but bra style - different breast shapes work better with different cup constructions. Don't hesitate to try multiple sizes and styles to find your perfect match.
Band Rides Up
Cause: Band is too loose
Solution: Try a smaller band size (sister size down)
Straps Dig In
Cause: Band too big, straps compensating
Solution: Decrease band size for proper support distribution
Cup Spillage (Quadboob)
Cause: Cup size too small
Solution: Increase cup size or try a different cup style
Cup Gaping
Cause: Cup too large or wrong shape
Solution: Decrease cup size or try a different cup style (e.g., demi vs full coverage)
Brand Variations & Sizing
Different brands have unique fitting philosophies and target demographics, leading to size variations even within the same country. European brands often run smaller in the band, while some American brands run large in the cup. Understanding these variations helps you adjust your size when trying new brands. Always consult brand-specific size charts and customer reviews for the most accurate fit information.
🇺🇸 US Brands
- Victoria's Secret: Runs small in band
- ThirdLove: True to size, half-cup options
- Soma: Generous in cup, snug in band
- Wacoal: Runs large in cup
🇪🇺 European Brands
- Chantelle: French sizing, runs small
- Prima Donna: Generous cups, firm bands
- Simone Perele: True to EU sizing
- Aubade: Runs small overall
Smart Shopping Tips
Armed with your measurements and size knowledge, you can shop confidently both online and in-store. Understanding return policies, reading reviews, and knowing when to seek professional fitting help ensures successful purchases. Remember that even within your size, different styles will fit differently based on your breast shape and personal preferences.
🛍️ Shopping Checklist
Online Shopping
- ✓ Check size charts for each brand
- ✓ Read customer reviews for fit info
- ✓ Order multiple sizes if unsure
- ✓ Verify return/exchange policy
- ✓ Look for adjustable features
In-Store Shopping
- ✓ Get fitted at the beginning
- ✓ Try multiple styles in your size
- ✓ Test movement and comfort
- ✓ Check fit with different clothes
- ✓ Buy on loosest hook setting
Bra Care & Longevity
Proper care extends the life of your bras and maintains their fit. Most bras last 6-12 months with regular wear, but proper care can extend this. Hand washing is ideal, but gentle machine washing in a lingerie bag works too. Never put bras in the dryer - heat breaks down elastic. Rotate between multiple bras to allow elastic recovery between wears. Store bras properly to maintain cup shape.
Key Takeaways for Perfect Bra Fit
Accurate measurements are essential - measure your band (underbust) and bust carefully, preferably with help. Use our calculator to determine your size in US, UK, and EU systems. Remember that sister sizes offer alternatives with the same cup volume but different band sizes for flexibility in fit.
A properly fitted bra has the band level and snug (providing 80% of support), cups that fully contain breast tissue without gaps or spillage, a center gore that lies flat, and comfortable straps. Check your fit every 6-12 months or with significant body changes. Understanding proper fit signs ensures comfort and support.
Sizes vary between brands and countries - always check specific size charts and reviews. European brands often run smaller, while some US brands run large. The traditional "+4" method is outdated; modern bras work best with actual measurements or minimal addition. Learn about brand variations for successful shopping.
Common fit problems have simple solutions: band riding up means it's too loose, straps digging in indicates the band is too big, and cup spillage or gaping means wrong cup size. Don't hesitate to try different styles and sizes. Use our Body Type Calculator to understand your shape better.