bra size calculator

Find Your Perfect Fit with Accurate Measurements

Calculate Your Bra Size

Understanding Bra Sizing: A Comprehensive Guide

Finding the perfect bra size is essential for comfort, support, and confidence. Studies show that up to 80% of women wear the wrong bra size, leading to discomfort, poor posture, and inadequate support. Our bra size calculator helps you determine your accurate measurements using the internationally recognized measurement method.

How Bra Sizing Works

Bra sizes consist of two components: the band size (number) and the cup size (letter). The band size represents the measurement around your ribcage, while the cup size indicates the volume of your breasts relative to your band size.

The cup size is determined by calculating the difference between your bust measurement and your band measurement. Each inch of difference corresponds to a cup size, starting with AA for a 0-1 inch difference, A for 1 inch, B for 2 inches, and so on.

How to Measure Yourself Correctly

Band Measurement:

• Stand in front of a mirror wearing a non-padded bra or no bra
• Wrap a soft measuring tape around your ribcage, directly under your bust
• Keep the tape parallel to the ground and snug but not tight
• Exhale naturally and take the measurement
• Round to the nearest whole number

Bust Measurement:

• Keep the measuring tape parallel to the ground
• Wrap it around the fullest part of your bust
• Don't pull the tape too tight – it should lie flat against your skin
• Stand up straight with your arms at your sides
• Round to the nearest whole number

Pro Tip: Measure yourself multiple times to ensure accuracy. Your measurements can fluctuate throughout your menstrual cycle, so consider measuring on different days for the most accurate average.

Understanding Cup Sizes

Cup sizes represent the volume of breast tissue and are calculated based on the difference between your bust and band measurements:

• AA: Less than 1 inch difference
• A: 1 inch difference
• B: 2 inches difference
• C: 3 inches difference
• D: 4 inches difference
• DD/E: 5 inches difference
• DDD/F: 6 inches difference
• G: 7 inches difference
• H: 8 inches difference
• I: 9 inches difference
• J: 10 inches difference

What Are Sister Sizes?

Sister sizes are alternative bra sizes that have the same cup volume but different band sizes. Understanding sister sizes can help you find a better fit when your calculated size doesn't feel quite right.

The principle is simple: when you go up one band size, you go down one cup size to maintain the same cup volume, and vice versa. For example, if you're a 34C, your sister sizes would be:

• Smaller band, larger cup: 32D (tighter band, same volume)
• Larger band, smaller cup: 36B (looser band, same volume)

Sister sizes are particularly useful when a bra fits well in the cup but not in the band, or vice versa.

Common Bra Fitting Problems and Solutions

Band Riding Up: If the band rides up your back, you need a smaller band size. The band should sit level around your torso and provide most of the support (about 80%).

Cups Gaping: If there's empty space in the cups, you need a smaller cup size. Gaping can also occur if the bra style doesn't match your breast shape.

Spillage or Bulging: If breast tissue spills over the top or sides of the cups, you need a larger cup size. This is one of the most common signs of an ill-fitting bra.

Straps Digging In: If the straps are uncomfortable or leaving marks, your band size might be too large. The band should provide primary support, not the straps.

Center Gore Not Lying Flat: The center piece between the cups should lie flat against your sternum. If it doesn't, you may need a larger cup size.

Different Sizing Systems Around the World

Bra sizing varies by region, which can be confusing when shopping internationally:

US/UK Sizing: Uses inches for band size (32, 34, 36, etc.) and letters for cup size (A, B, C, D, etc.). The UK system is similar but may have slight variations in larger cup sizes.

European Sizing: Uses centimeters for band size (70, 75, 80, etc.) and letters for cup size. To convert from US to EU sizing, subtract 2 from the US band size and multiply by 2.5. For example, a US 34 equals an EU 75 (34-2=32, 32×2.5=80, rounded to 75).

Australian Sizing: Similar to UK sizing but may have different labeling conventions for larger cup sizes.

Remember: These conversions are approximate. Always check the brand's specific sizing chart as sizing can vary significantly between manufacturers.

How Often Should You Measure?

Your bra size can change throughout your life due to various factors:

• Weight fluctuations: Gaining or losing as little as 5-10 pounds can affect your bra size
• Pregnancy and nursing: Breast size typically increases during pregnancy and while breastfeeding
• Hormonal changes: Birth control, menopause, and hormonal medications can impact breast size
• Age: Breast tissue changes with age, affecting shape and size
• Exercise: Changes in muscle tone can affect band measurement

It's recommended to measure yourself every 6-12 months, or whenever you notice your bras fitting differently.

Tips for Finding the Perfect Bra

• Always try on bras before purchasing when possible
• Try on multiple sizes, including sister sizes
• Fasten the bra on the loosest hook (bands stretch over time)
• Adjust the straps after fastening the band
• Bend over and ensure your breasts fill the cups without spillage
• Move around to test comfort – raise your arms, twist, and bend
• Check that the band is level and doesn't ride up
• Ensure the center gore lies flat against your sternum
• Consider different styles for different breast shapes
• Don't be loyal to one size – try what fits, not what the tag says

Breast Shape Matters Too

Beyond size, breast shape plays a crucial role in finding the right bra. Common breast shapes include:

Round: Equal fullness at top and bottom – works well with most bra styles

East-West: Nipples point outward – T-shirt bras and front-closure bras work well

Side-Set: More space between breasts – push-up and plunge styles work best

Teardrop: More fullness at bottom – balconette and demi-cup styles are flattering

Asymmetric: One breast larger than the other – fit to the larger breast and use inserts if needed

Bell-Shaped: Slimmer at top, fuller at bottom – full-coverage bras provide best support

The Importance of Professional Fitting

While online calculators provide excellent starting points, nothing replaces a professional bra fitting. Many lingerie stores offer free fitting services with trained specialists who can:

• Account for breast shape and asymmetry
• Recommend specific styles for your body type
• Identify fitting issues you might not notice
• Help you understand how different brands fit
• Provide personalized advice on bra care and rotation

Investing in Quality

A well-fitting bra is an investment in your comfort and health. Quality bras typically last 6-9 months with proper care. Signs it's time to replace your bra include:

• The band has stretched and no longer feels snug on the tightest hook
• Wires are poking through or distorted
• Cups have lost their shape
• Straps have lost elasticity
• The bra no longer provides adequate support

Bra Care Tips: Hand wash or use a lingerie bag, air dry instead of machine drying, rotate between at least 3 bras to extend their life, and store bras flat or cups nested together to maintain shape.

Conclusion

Finding your correct bra size is a journey that combines accurate measurements, understanding your breast shape, and trying different styles. Use this calculator as your starting point, but remember that the perfect fit is ultimately about how the bra feels on your body. Don't be afraid to experiment with different sizes and styles, and consider getting professionally fitted at least once to ensure you're on the right track.

A properly fitting bra can improve your posture, reduce back and shoulder pain, enhance your silhouette, and boost your confidence. Take the time to find your perfect fit – your body will thank you!