About BraSizeChecker
BraSizeChecker is an independent digital tool and reference hub designed to help individuals find an accurate starting bra size from home using modern fitting standards.
Why BraSizeChecker Exists
For decades, traditional bra fitting guides relied on the outdated "+4 method"—adding 4 to 5 inches to a person's underbust measurement. This resulted in millions of people wearing band sizes that were far too loose and cup sizes that were far too small.
BraSizeChecker was created to provide a modern, direct underbust calculation algorithm that anchors the bra band snugly against the ribcage where 80% of support belongs.
100% Independent & Brand-Neutral
BraSizeChecker is completely independent. We are not owned, operated, or sponsored by any lingerie manufacturer, brand, or retail outlet.
• Zero paid product placements • Objective conversion algorithms • Unbiased fit advice
Understanding Sizing Limitations
While our calculator provides a highly accurate modern fitting baseline, a calculated size is always a starting point, not a guaranteed medical prescription.
- Fabric Elasticity: Firm powernet elastic fits tighter than soft microfiber of the same size label.
- Cup Construction: Molded foam cups hold a fixed shape, whereas seamed fabric cups conform flexibly.
- Body Asymmetry: Most human bodies have slight breast size variations that require fitting the larger side.
Privacy & Editorial Team
Our calculator processes all underbust and bust inputs locally inside your browser. We do not create user profiles, require account sign-ups, or store personal measurement data.
All educational guides are researched, written, and maintained by the BraSizeChecker Editorial & Product Team with continuous updates.