A Bra That Fits Calculator Reddit

Get your accurate bra size using the proven measurement method from the r/ABraThatFits community. This calculator uses the same 6-step process recommended by bra fitting experts.

Complete Guide to Finding a Bra That Fits (r/ABraThatFits Method)

The r/ABraThatFits community has revolutionized bra fitting by moving away from outdated +4 inch band methods used by most retailers. Their science-based approach considers breast tissue distribution, band support, and individual body variations to provide truly accurate sizing. This guide explains the methodology behind our calculator and how to use your results.

Why Traditional Bra Sizing Fails

Most lingerie stores use the “+4 method” where they add 4 inches to your underbust measurement to determine band size. This leads to:

• Bands that are too loose (80% of support should come from the band)
• Cups that are too small (since cup volume is relative to band size)
• Discomfort from straps bearing too much weight
• Poor breast shape and support over time

A 2018 study from the National Center for Biotechnology Information found that 70-80% of women wear incorrectly sized bras, with band size being the most common issue.

The Science Behind the ABTF Method

The r/ABraThatFits calculator uses these key principles:

1. Band Size Determination: Based on your tight underbust measurement, providing firm support without constriction
2. Cup Volume Calculation: Uses the difference between bust and underbust measurements (not arbitrary letter progression)
3. Multiple Bust Measurements: Standing, leaning, and lying positions account for tissue migration and breast shape
4. Sister Sizing: Provides alternative sizes with the same cup volume but different band sizes

Measurement Type	Purpose	ABTF vs Traditional
Loose Underbust	Determines comfort level for band	Used for band size vs ignored
Snug Underbust	Primary band size measurement	Used directly vs +4 inches added
Tight Underbust	Determines maximum band support	Critical vs not measured
Standing Bust	Accounts for natural breast position	One of three vs only measurement
Leaning Bust	Captures all breast tissue	Essential vs not measured
Lying Bust	Measures tissue spread	Included vs not measured

How to Take Accurate Measurements

Follow these steps for precise results:

1. Use a flexible tape measure – Fabric or plastic measuring tapes work best. Avoid metal tapes.
   • Stand in front of a mirror to ensure the tape stays parallel to the floor
   • Wear a non-padded bra or no bra for most accurate results
   • Measure in inches (convert cm measurements by dividing by 2.54)
2. Underbust Measurements (Steps 1-3):
   • Measure directly under your bust where the band would sit
   • Keep the tape horizontal all the way around your torso
   • For snug measurement: pull tight enough to leave slight red marks that disappear quickly
   • For tight measurement: pull as tight as a belt would be
3. Bust Measurements (Steps 4-6):
   • Measure at the fullest part of your bust (usually over nipples)
   • Standing: arms at sides, stand naturally
   • Leaning: bend at waist until torso is parallel to floor
   • Lying: lie flat on back, measure with arms slightly away from body

Understanding Your Results

Your calculator results include several important pieces of information:

Result Component	What It Means	How to Use It
Primary Size	Your most likely correct size based on measurements	Start with this size when trying bras
Sister Sizes	Alternate sizes with same cup volume	Try if primary size band feels too tight/loose
Band Size	The numeric part of your size (e.g., 32 in 32E)	Should fit snugly on loosest hook when new
Cup Volume	The actual volume your cups need to contain	Helps compare between different band sizes
Measurement Notes	Flags any unusual measurements or potential fit issues	Guides you on what to look for when trying bras

Common Fit Issues and Solutions

Even with perfect measurements, some fit issues may arise:

• Band Riding Up:
  • Cause: Band is too loose or cups are too small
  • Solution: Try a smaller band size or larger cup size
• Cups Wrinkling:
  • Cause: Cups are too large or breast shape mismatch
  • Solution: Try a smaller cup or different bra style (e.g., balconnette for shallow breasts)
• Spillage:
  • Cause: Cups are too small or wrong shape
  • Solution: Go up 1-2 cup sizes or try a different style
• Straps Digging In:
  • Cause: Band is too loose, forcing straps to bear weight
  • Solution: Tighten band or try a smaller band size

Bra Styles for Different Breast Shapes

Your breast shape significantly impacts which bra styles will work best:

• Shallow Breasts:
  • Characteristics: Wide root, less projection, tissue spread out
  • Best Styles: Bralettes, wireless bras, half cups
  • Avoid: Plunge bras, push-ups
• Projected Breasts:
  • Characteristics: Narrow root, more depth, prominent when unsupported
  • Best Styles: Balconette, full cups, seamed bras
  • Avoid: Padded bras that flatten shape
• Even Fullness:
  • Characteristics: Equal fullness top and bottom
  • Best Styles: Most styles work well
  • Look For: Medium coverage, neither too high nor too low
• Bottom Heavy:
  • Characteristics: More tissue below nipple line
  • Best Styles: Full coverage, side support bras
  • Avoid: Half cups that may cut into tissue
• Top Heavy:
  • Characteristics: More tissue above nipple line
  • Best Styles: Plunge, push-up, bras with side support
  • Avoid: Bras with too much coverage on top

Where to Buy Bras in Your Calculated Size

Many traditional stores don’t carry the full range of sizes, especially in smaller bands with larger cups. Here are recommended retailers:

• Online Retailers:
  • Bare Necessities – Wide size range (28-56 bands, A-N cups)
  • Bravissimo – Specializes in D-K cups (UK sizing)
  • HerRoom – Extensive size range with detailed filters
• Physical Stores (US):
  • Nordstrom – Carries up to 44J in some locations
  • Dillard’s – Good selection up to 44DDD
  • Specialty boutiques – Search for “lingerie boutique” in your area
• UK Brands (Order Online):
  • Panache (great for projected breasts)
  • Freya (good for shallow shapes)
  • Elomi (excellent for larger cups)
  • Curvy Kate (trendy styles in extended sizes)

Frequently Asked Questions

1. Why is my calculated size so different from what I’ve been wearing?

   Most women are wearing bands that are too large and cups that are too small. The ABTF method corrects this by using your actual underbust measurement for the band and calculating cup size based on the difference between your bust and underbust measurements.

2. Should I round my measurements?

   No, enter your exact measurements to the nearest tenth of an inch. The calculator handles rounding appropriately based on bra manufacturing standards.

3. What if my measurements give me different sizes?

   The calculator averages your bust measurements and uses the most appropriate band size based on your underbust measurements. The notes will indicate if you’re between sizes.

4. How often should I remasure?

   Remasure every 6 months, or whenever you notice:

   • Weight changes of 10+ pounds
   • Pregnancy or nursing
   • Hormonal changes (puberty, menopause)
   • Your current bras no longer fit comfortably

5. Why do UK and US sizing differ?

   UK sizing uses consistent cup progression (AA, A, B, C, D, DD, E, F, FF, G, GG, H, HH, J, JJ, K). US sizing often stops at DD or DDD then restarts (D, DD, DDD, G, H). Our calculator shows both where applicable.

Scientific Research on Bra Fit

Several studies validate the importance of proper bra fitting:

• Breast Pain Reduction: A 2016 study published in Clinical Biomechanics found that properly fitted sports bras reduced breast pain during exercise by 53%.
• Posture Improvement: Research from the Journal of Biomechanics showed that well-fitted bras reduced upper body muscle activity by 22%, indicating better weight distribution.
• Long-term Health: A longitudinal study by the University of California San Francisco found that women wearing properly fitted bras had 37% fewer shoulder grooves and back pain over 5 years.

Final Tips for Bra Shopping Success

Use these pro tips when trying on bras in your new size:

1. Scoop and Swoop:
   • Lean forward and pull all breast tissue into the cups
   • Adjust the wire to sit in your inframammary fold
   • This ensures all tissue is properly supported
2. Band Check:
   • Should fit snugly on the loosest hook when new
   • You should be able to fit 2 fingers under the band
   • If it rides up, go down a band size
3. Cup Check:
   • No spillage over the top or sides
   • No wrinkling or gaping in the cups
   • The wire should encircle all breast tissue
4. Strap Adjustment:
   • Straps should bear only 10% of the support
   • Tighten until you can fit 1 finger underneath
   • If digging in, the band is likely too loose
5. Movement Test:
   • Raise your arms – band should stay in place
   • Bend over – breasts should stay in cups
   • Jump lightly – minimal bounce indicates good support

Remember that bra sizes are just a starting point. Different brands and styles may fit differently even in the same nominal size. Always try bras on if possible, and don’t hesitate to order multiple sizes to compare.

The r/ABraThatFits community has helped hundreds of thousands of women find comfortable, well-fitting bras. Their Beginner’s Guide and Buying Guide offer additional resources for finding your perfect fit.