Bra Size Calculator in Inches

Find your perfect bra size using our inch-based calculator. Measure your underbust and bust to determine your accurate band and cup size. Follow our simple guide below for the most precise results.

Underbust Measurement (inches): Bust Measurement (inches):

How to Measure Your Bra Size in Inches

Finding your correct bra size begins with accurate measurements. Follow these steps carefully to ensure the best fit:

Step-by-Step Measurement Guide

1. Prepare for Measurement

Wear a non-padded bra or no bra for most accurate results
Stand straight with arms at your sides
Use a soft measuring tape (fabric or plastic)
Have someone help you for more precise measurements

2. Measure Your Underbust

Wrap the tape measure snugly around your ribcage, just below your breasts
Ensure the tape is parallel to the floor all around
Take a normal breath and measure on the exhale
Record this number to the nearest half inch

3. Measure Your Bust

Wrap the tape measure around the fullest part of your bust
Keep the tape parallel to the floor and don't compress your breasts
Don't pull the tape too tight - it should rest gently
Record this number to the nearest half inch

4. Calculate Your Size

Your band size is typically your underbust measurement rounded to the nearest even number
Subtract your band size from your bust measurement to determine cup size
Each inch difference represents one cup size (1" = A, 2" = B, etc.)

Understanding Bra Size Components

Band Size

The band size (e.g., 32, 34, 36) represents the measurement around your ribcage just below your breasts. This number should be close to your actual underbust measurement in inches. The band provides about 80% of a bra's support, so proper fit is crucial.

Cup Size

The cup size (e.g., A, B, C) represents the difference between your bust measurement and your band size. Cup sizes are relative to band size - a 32D has smaller cups than a 36D. The cup should fully contain your breast tissue without gaps or spillage.

Common Measurement Mistakes to Avoid

Measuring over clothing: This can add inches to your measurements
Pulling the tape too tight: Leads to an overly tight band size
Measuring at an angle: The tape should be parallel to the floor
Measuring while inhaling: Can artificially increase measurements
Using an old measuring tape: Stretched tapes give inaccurate readings
Measuring alone: Having help improves accuracy

International Bra Size Conversion

US Size	UK Size	EU Size	Band (inches)	Band (cm)
30A	30A	65A	28-30	71-76
32B	32B	70B	30-32	76-81
34C	34C	75C	32-34	81-86
36D	36D	80D	34-36	86-91
38DD	38DD	85E	36-38	91-97

Cup Size Progression Chart

Difference (inches)	US Cup Size	UK Cup Size
0-0.5	AA	AA
1	A	A
2	B	B
3	C	C
4	D	D
5	DD	DD
6	DDD/F	E
7	G	F
8	H	FF

Special Considerations

For Larger Busts

Consider sizing up in the band for comfort if between sizes
Look for bras with wider bands and straps for better support
Full-cup or balconette styles often provide better coverage

For Smaller Busts

You may prefer a snugger band for better fit
Bralettes and wireless styles can be comfortable options
Push-up or padded styles can enhance shape if desired

For Asymmetrical Breasts

Measure both sides and use the larger measurement
Consider removable padding to balance asymmetry
Look for stretch lace cups that accommodate differences

Frequently Asked Questions

How often should I measure my bra size?

It's recommended to measure every 6-12 months or after significant weight changes (gain/loss of 10+ pounds), pregnancy, or surgery that affects your breasts.

Why does my bra size vary between brands?

Different brands use slightly different sizing standards and fit models. Some brands run small or large in band or cup. Always check brand-specific sizing charts when available.

What if my measurement falls between band sizes?

If your underbust measurement is an odd number (e.g., 31"), try both the size below (30) and above (32). Choose based on comfort - the band should be snug but not painful.

How tight should the measuring tape be?

The underbust measurement should be snug like a properly fitted bra band. The bust measurement should be taken loosely around the fullest part without compressing breast tissue.

What if my cup size calculation seems too large or small?

The calculator provides a starting point. If the result seems off, double-check your measurements. Some breast shapes may need adjustments - try the calculated size and sister sizes.

How do pregnancy and breastfeeding affect bra size?

Breast size often increases during pregnancy and fluctuates during breastfeeding. You may need to measure more frequently during these periods and consider nursing bras.

What's the difference between US and UK sizing?

Band sizing is similar, but cup sizing differs after DD. US sizing typically goes D-DD-DDD-G while UK goes D-DD-E-F. Always check which system a brand uses.

Why is proper bra sizing important?

A well-fitted bra improves comfort, posture, and breast support. Ill-fitting bras can cause back pain, shoulder grooves, and even skin irritation or breathing difficulties.

Signs of a Well-Fitted Bra

Band Fit

Snug but comfortable on the loosest hook (allows for stretch over time)
Parallel to the floor all around your body
You can fit two fingers underneath but not pull it more than 2 inches away

Cup Fit

Breasts fully contained without spillage or gaping
Underwire (if present) follows your breast root without poking
Center gore lies flat against your sternum

Straps

Adjustable to stay in place without digging into shoulders
Provide about 20% of the support (not bearing most of the weight)
Not leaving red marks or causing discomfort

Professional Bra Fitting vs. Self-Measurement

Professional Fitting

Benefits:

Expertise in assessing fit and shape
Access to a wide range of sizes and styles
Ability to try on multiple options

Considerations:

Quality varies by fitter experience
Some stores may carry limited size ranges
Can be time-consuming

Self-Measurement