Bra Size Calculator
Calculate bra size from band and bust measurements.
Measurements
inches (around ribcage)
inches (fullest part)
- Measure band size around ribcage, just below bust
- Measure bust size around fullest part of bust
- Keep measuring tape level and snug but not tight
- Wear a well-fitting, unpadded bra or no bra
Bra Size
US Size
34B
UK Size
34B
Band Size
34
Cup Size
B
US: B | UK: B
Difference:
2.0 inches
Measurements:
Band: 34.0" | Bust: 36.0"
About This Calculator
The Bra Size Calculator helps you determine your bra size based on band and bust measurements. It calculates both US and UK bra sizes, which can differ for larger cup sizes. Proper bra sizing is important for comfort and support.
To use this calculator, measure your band size (around your ribcage, just below your bust) and your bust size (around the fullest part of your bust). The calculator will determine your cup size based on the difference between these measurements.
Note: This calculator provides an estimate. Bra sizing can vary between brands, so it's recommended to try on bras for the best fit.
Formula & Calculation Method
Bra Size Calculation:
Band Size:
Measure around ribcage (just below bust)
Round to nearest even number
Cup Size:
Difference = Bust Size - Band Size
Cup size based on difference:
0-0.5": AA | 1": A | 2": B | 3": C
4": D | 5": DD/E | 6": DDD/F | etc.
Bra Size:
Size = Band Size + Cup Letter
The band size is the measurement around your ribcage, rounded to the nearest even number. The cup size is determined by the difference between your bust measurement and band measurement. Each inch of difference typically corresponds to one cup size.
How to Use This Calculator
- Measure Band Size: Measure around your ribcage, just below your bust, keeping the tape level.
- Measure Bust Size: Measure around the fullest part of your bust, keeping the tape level.
- Enter Measurements: Input your band and bust measurements in inches or centimeters.
- View Results: See your calculated bra size in both US and UK sizing systems.
Frequently Asked Questions
How do I measure my band size?
Measure around your ribcage, just below your bust, keeping the measuring tape level and snug (but not tight). Round this measurement to the nearest even number to get your band size.
How do I measure my bust size?
Measure around the fullest part of your bust, keeping the measuring tape level. Make sure you're wearing a well-fitting, unpadded bra or no bra at all for the most accurate measurement.
What is the difference between US and UK sizing?
US and UK sizing are the same for smaller cup sizes (A-D). For larger sizes, UK sizing uses double letters (DD, E, F, FF, G, GG) while US sizing uses triple D's and single letters (DDD, F, G, H, I, J).
Why does my calculated size not fit?
Bra sizing can vary significantly between brands and styles. This calculator provides an estimate based on standard sizing. It's recommended to try on bras in different sizes and styles to find the best fit for your body.
Expert Reviewed
This calculator was reviewed by NumCalculators Editorial Team, Multi-disciplinary Expert Team