Bra Size Calculator
Find your perfect bra size with our comprehensive calculator. Get accurate measurements using band size and bust measurements in both inches and centimeters.
Measurements
Your Bra Size
US/UK Sizes
European Sizes
Measurement Summary
Sister Sizes
Fit Recommendations
How to Measure
Band Size (Under Bust)
Wear a non-padded, well-fitting bra or go braless.
Wrap the measuring tape around your ribcage, just under your bust.
Keep the tape snug but not tight, and ensure it's level all around.
Take the measurement at the end of a normal exhale.
Bust Size (Over Bust)
Keep wearing the same bra or remain braless.
Wrap the tape around the fullest part of your bust.
Keep the tape level and not too tight - it should lie flat against your skin.
Stand up straight and look straight ahead while measuring.
💡 Pro Tips
- • Measure yourself or ask someone to help for more accurate results
- • Take measurements at the same time of day for consistency
- • Avoid measuring during your menstrual cycle when breasts may be swollen
- • Round measurements to the nearest half inch or centimeter
- • Re-measure every 6 months as your body can change
Understanding Bra Sizing
Cup Size Guide
Difference to Cup Size
Extended Sizes
Sizing Methods
Standard Method
Uses your actual under-bust measurement as the band size. More accurate for most people.
Plus 4 Method
Adds 4-5 inches to under-bust measurement. Traditional method, less commonly used today.
Sister Sizes
Sister sizes have the same cup volume but different band sizes. When you go up a band size, go down a cup size, and vice versa.
When to Use This Calculator
Shopping for Bras
- • Online bra shopping
- • Trying new brands
- • International size conversion
- • Finding your starting size
- • Gift shopping
Body Changes
- • Weight fluctuations
- • Pregnancy and nursing
- • Hormonal changes
- • Age-related changes
- • Post-surgery fitting
Comfort & Health
- • Improving comfort
- • Better support
- • Reducing back pain
- • Athletic activities
- • Professional fitting prep
Example Calculations
Example 1: Standard Method
Example 2: Plus 4 Method
Example 3: Metric Measurements
Frequently Asked Questions
How often should I measure my bra size?
It's recommended to measure your bra size every 6 months, as your body can change due to weight fluctuations, hormonal changes, age, or lifestyle factors. Also measure after significant life events like pregnancy, weight loss/gain, or surgery.
Why do different brands fit differently?
Bra sizing isn't standardized across brands. Each manufacturer has slightly different measurements for the same size. Additionally, different styles (push-up, sports, minimizer) fit differently even within the same brand. Always try on or check the brand's specific sizing chart.
What if I'm between sizes?
If you're between band sizes, choose the smaller size for better support. If you're between cup sizes, choose the larger cup. You can also try sister sizes - they have the same cup volume but different band fits.
Should I use the plus 4 method?
The plus 4 method is outdated and generally not recommended. It was created when bras were made with less stretchy materials. Modern bras are designed to work with your actual under-bust measurement for better support and comfort.
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