Bra Size to Measurements Converter
Estimate reference underbust and bust ranges associated with a US bra-size label.
How the reference measurements are estimated
This tool reverses BraSizePRO's simplified cup-index relationship to produce a measurement range associated with a US size label. It is a reference lookup, not a claim that everyone wearing the same label has the same body dimensions.
- Underbust: the entered band is represented as a range of one inch below to one inch above the band number.
- Bust: the cup index is added to the band and a half-inch margin is applied around that reference.
- Units: the resulting reference values can be displayed in inches or converted to centimeters.
Body proportions, measurement technique, garment construction, and manufacturer sizing can all produce different real-world fits. See the full methodology.
Frequently Asked Questions
Answers about sizing methods, measurements, and fit considerations.
Can two people with the same bra size have different body dimensions?
Yes. For example, a 34D fits someone with a 33-35 inch underbust and a 37-39 inch bust. A size label is not a complete description of body shape or garment fit. The ranges shown here are estimates generated from the calculator reference method, so people with the same label can still have different proportions, shapes, or preferred garment fits.
Sizing References
- ASTM D5586: Standard Tables of Body Measurements for Apparel Sizing