April 2, 2025•8 •
- [1]r/ABraThatFits Community. Sister sizes methodology and community-validated bra sizing guide. 500,000+ member community. Reddit r/ABraThatFits
- [2]A Bra That Fits Calculator. ABTF 6-measurement method and sister sizing system. abrathatfits.org
- [3]Wood, K., Cameron, M., & Cameron, K. (2008). Breast size and bra fitting issues in 16-39 year old women. Journal of Plastic, Reconstructive & Aesthetic Surgery, 61(4), 398-404. PubMed
- [4]International Organization for Standardization. ISO 4416:1981 — Size designation of clothes — Underwear, nightwear and shirts. ISO
- [5]Greenbaum, A.R., Heslop, T., Morris, J., & Dunn, K.W. (2003). An investigation of the suitability of bra fit in women referred for reduction mammaplasty. British Journal of Plastic Surgery, 56(7), 675-680. PubMed
Bra Calculator Editorial Team
Researched & Written byCommunity-Validated
Our content is researched, written, and regularly updated by our editorial team using the A Bra That Fits (ABTF) methodology — the same approach validated by the 500,000+ member r/ABraThatFits community. We cite peer-reviewed research, lingerie industry standards, and community data. Our calculators process data locally in your browser; we do not collect body measurements.
We use the modern 6-measurement ABTF method rather than the outdated +4 inch rule. This approach has been independently validated by the r/ABraThatFits community to produce more accurate and comfortable bra sizes than traditional two-measurement methods.
Last reviewed: July 2025