Welcome to the definitive **Reddit Bra Size Calculator**, a specialized tool that applies the widely recognized “A Bra That Fits” (ABTF) measurement methodology. This calculator uses five distinct measurements to provide a more accurate, three-dimensional estimate of your ideal bra size, moving beyond typical high-street sizing.
Reddit Bra Size Calculator
Reddit Bra Size Calculator Formula:
Average Bust (AB) = (Standing Bust + Leaning Bust + Lying Bust) / 3
Cup Volume Difference (Diff) = AB – Band
Cup Letter = Look up Diff in the Cup Progression Table.
Formula Source: A Bra That Fits (ABTF) Methodology
Variables:
- Snug Underbust: Your comfortable, level measurement directly beneath the bust. Used as the basis for the band size.
- Tight Underbust: The tightest measurement you can achieve beneath the bust, exhaling all air. This helps determine maximum compression and band comfort.
- Standing Bust: The measurement around the fullest part of the bust while standing straight.
- Leaning Bust: The measurement taken while leaning over parallel to the floor. This captures breast tissue volume more accurately.
- Lying Bust: The measurement taken while lying flat on your back. This helps account for the spread of breast tissue.
Related Calculators:
Bust to Cup Converter Sister Size Finder Metric to US Bra Size Sports Bra Size CalculatorWhat is the Reddit Bra Size Calculator?:
The “Reddit Bra Size Calculator” refers specifically to the methodology popularized by the r/ABraThatFits community. Unlike traditional methods that rely only on one or two measurements and often result in an underestimation of cup size (leading to the common “too tight band, too small cup” issue), this method uses five distinct measurements.
The core philosophy is that taking multiple bust measurements—standing, leaning, and lying—provides a more accurate average of breast volume. When this average volume is compared against a properly sized band (derived from the snug underbust), the resulting cup difference provides a much more precise cup volume recommendation.
How to Calculate Bra Size (Example):
- Input Measurements: Assume the following (in inches): Snug Underbust = 31, Tight Underbust = 29, Standing Bust = 36, Leaning Bust = 38, Lying Bust = 35.
- Determine Band Size: The Snug Underbust (31 in) is rounded up to the nearest even number. Result: 32 Band.
- Calculate Average Bust: $(36 + 38 + 35) / 3 = 109 / 3 \approx 36.33$ inches.
- Find Cup Difference: $36.33 – 32 = 4.33$ inches.
- Look up Cup Letter: A difference of 4 inches corresponds to a US DD/E cup.
- Final Estimated Size: 32DD/E.
Frequently Asked Questions (FAQ):
Why does this calculator give me a completely different size?
Traditional methods often add 4 inches to the underbust measurement, artificially inflating the band size and leading to a smaller, incorrect cup size. The ABTF method uses your actual underbust measurement for the band, ensuring a snug, supportive fit, which in turn reveals your true cup volume.
Should I use inches or centimeters?
Both are equally accurate, as long as you are consistent. This calculator handles the conversion and calculation internally. For the most precise results, using centimeters may provide slightly finer granularity for the decimal points.
What is “Sister Sizing”?
Sister sizes represent the same cup volume but on a different band size. For example, a 34C and a 32D are sister sizes. If your calculated size band is too tight, you can go up one band size and down one cup size (e.g., from 32DD to 34D) to maintain the volume.
What if my bust measurements vary wildly?
Significant variation (more than 2 inches) between Standing, Leaning, and Lying measurements often indicates projected breast shape. In such cases, the Leaning measurement is often the most accurate predictor of cup volume, though the calculator averages all three for a balanced result.