How to Use Our Accurate Bra Size Calculator
Finding your perfect bra size shouldn't be complicated. Our accurate calculator simplifies the process by using just two key measurements. Follow the steps below to get a reliable size recommendation in seconds, helping you shop with confidence.
Step 1: Measure Your Band Size
Using a soft measuring tape, measure around your ribcage directly under your bust. Make sure the tape is level and snug, but not too tight. This measurement is the foundation of your bra size, so it's important to get it right.
Step 2: Measure Your Bust Size
Now, measure around the fullest part of your bust, keeping the tape parallel to the floor. The tape should be comfortably loose, not compressing your chest. This number helps determine your cup size.
Step 3: Get Your Recommended Size
Enter your band and bust measurements into the fields above, select your preferred unit (inches or cm), and click "Calculate My Size." Our tool will instantly provide your recommended US, UK, and European bra sizes.
USA Bra Size Calculator and Chart
Bra sizing in the USA can be inconsistent between brands. Our calculator uses a standardized method to give you a dependable starting point. Use this tool and the information below to better understand American bra sizes.
US Standard Bra Sizing Chart
A bra size chart helps visualize the relationship between band and cup sizes. While our calculator automates this, a chart can be a useful quick reference. Remember that the cup volume changes with the band size, which is where sister sizes become helpful.
Plus Size Bra Fitting
For plus-size individuals, finding a bra that offers both comfort and support is essential. Our calculator is designed to work for a wide range of body types. When fitting, prioritize a snug band, cups that fully contain your breast tissue without spillage, and comfortable straps.
Common Fitting Problems to Avoid
If your bra's band rides up your back, it's too loose. If the cups are gapping, the cup size may be too large. Conversely, spillage at the top or sides means the cup is too small. Use our calculator to find a better starting point and avoid these common issues.
Understanding International Bra Sizing
Shopping online or while traveling can be confusing due to different international sizing systems. Our calculator helps by converting your size automatically, but here is a quick guide to the main differences.
US to UK Bra Size Conversion
US and UK bra sizing are similar for smaller cups (A-D), but they diverge significantly after a DD cup. The UK system uses double letters like FF, GG, and HH, whereas the US system often uses DDD, G, H, and so on. Our calculator correctly handles this conversion for you.
US to European (EU) Bra Size Conversion
The European sizing system is fundamentally different. It uses centimeters for the band size (e.g., 75, 80, 85) instead of inches (34, 36, 38). The cup letters are generally similar to the US system, making band conversion the most critical part.
What Are Sister Sizes?
A sister size is an alternative bra size where the cup volume remains the same, even though the band and cup letter change. This concept is incredibly useful if your recommended size doesn't fit perfectly or is out of stock.
How Our Sister Size Calculator Works
The rule is simple: if you go down one size in the band, you must go up one size in the cup to maintain the same volume (e.g., a 34C's sister size is 32D). Our tool automatically provides these alternatives to give you more fitting options.
Sister Size Chart for USA Sizes
A sister size chart allows you to quickly see your alternatives. For example, if you wear a 36D, your smaller sister size is 34DD, and your larger one is 38C. Knowing these options can make finding a comfortable bra much easier.