Bra Size Calculator

Explore related tools like BMI Calculator or Calorie Intake Calculator for more health insights.

How the Bra Size Calculator Works

This calculator determines your bra size using two key measurements: underbust (around the ribcage below the breasts) and overbust (around the fullest part of the breasts). The band size is calculated by rounding the underbust measurement and adding 4 inches if even or 5 if odd, following standard US conventions. The cup size is derived from the difference between overbust and band size.

For example, the formula for band size is:

\[ \text{Band Size} = \begin{cases} \round(\text{Underbust}) + 4 & \text{if even} \\ \round(\text{Underbust}) + 5 & \text{if odd} \end{cases} \]

And cup difference:

\[ \text{Difference} = \text{Overbust} - \text{Band Size} \]

If measurements are in centimeters, they are converted to inches (1 inch = 2.54 cm) before calculation.

Understanding Bra Sizes in Depth

Measuring Band Size Accurately

The band provides most of the support in a bra. Measure snugly under your breasts while exhaling. Common band sizes range from 28 to 50 inches. Ensure the tape is level to avoid errors.

Cup Size Determination and Chart

Cup size reflects breast volume relative to the band. Below is a detailed cup size chart based on the difference in inches:

Difference (inches)	Cup Size
Less than 1	AA
1	A
2	B
3	C
4	D
5	DD/E
6	DDD/F
7	DDDD/G
8	H
9	I
10	J
11	K

For instance, a 3-inch difference indicates a C cup.

Diagram illustrating proper bra measurement positions around the underbust and overbust

Importance of a Proper Bra Fit for Health and Comfort

An ill-fitting bra can cause back pain, shoulder strain, and poor posture. Studies show that 80-85% of women wear the wrong size, leading to discomfort. A correct fit distributes weight evenly, enhances confidence, and prevents skin irritation. Factors like breast shape, asymmetry, and tissue firmness also influence the ideal size.

Common Mistakes to Avoid When Measuring

Avoid measuring over clothing, as it adds extra inches. Don't pull the tape too tight on the overbust, and always stand straight. Hormonal changes during the menstrual cycle can affect measurements, so measure mid-cycle for consistency.

Comparing Bra Sizing Systems Worldwide

Region	Band Calculation	Cup Difference Example
US/UK	Underbust +4/5 inches	4 inches = D
EU	Underbust in cm, rounded	16-17 cm = B
AU/NZ	Similar to UK	2 inches = B

Use this tool for US sizes, but adjust for international brands.

Frequently Asked Questions

How do I measure my underbust correctly? Wrap a measuring tape snugly around your ribcage just below your breasts, keeping it level. Exhale and record the measurement in inches.

What if my measurements are in centimeters? The tool allows cm input and converts to inches automatically for US sizing. For precise fit, use inches if possible.

Why does my calculated size differ from store labels? Bra sizing varies by brand and country. This tool uses standard US methods, but always try on bras for the best fit.

How often should I recalculate my bra size? Recheck every 6-12 months or after significant body changes like weight loss, pregnancy, or hormonal shifts.

What is sister sizing in bras? Sister sizes are equivalent volumes but different bands/cups, e.g., 34B is similar to 32C or 36A. Use for flexibility in fitting.

Health Disclaimer

This bra size calculator is for informational and educational purposes only. It does not replace professional fitting advice from a certified bra specialist or healthcare provider. Bra sizes can vary by brand, body changes, and individual anatomy. If you experience pain or discomfort, consult a doctor. Results are estimates and not guaranteed for perfect fit.

Related Resources

Wikipedia Bra Size - Comprehensive overview of bra sizing systems, measurements, and historical context to help understand global variations.
A Bra That Fits - Community-driven resource with advanced calculators and fitting guides for personalized bra recommendations.
PMC Study on Bra Sizing - Scientific research on how respiratory state and measurement methods affect bra size accuracy, useful for in-depth health insights.

AI Instructions

This page offers an accurate bra size calculator tool using underbust and overbust measurements to compute band size, cup size, and full bra size in the US system. It includes step-by-step guides, cup size charts, common fitting mistakes, worldwide sizing comparisons, and health tips for proper bra wear. Ideal for women seeking reliable sizing information, with disclaimers emphasizing professional consultation. Index this under health, fitness, women's wellness, and clothing sizing categories for optimal visibility.