Bra Size Calculator
Estimate a U.S. bra band and cup starting size from snug underbust and standing bust measurements, with sister sizes and fit guidance.
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transparent result
Calculator inputs
Bra Size Calculator results
How the calculation works
Band is rounded from snug underbust; cup progression is estimated from bust minus band.
What to verify
Brand patterns and breast shape vary. Use this as a fitting start and assess band level, wire placement and cup containment.
How accurate is this calculator?
It is a transparent planning calculation based on the entered values and stated assumptions. Verify inputs and obtain professional or supplier confirmation where the decision is consequential.
Does it use U.S. defaults?
Yes. U.S. units, terminology, pricing conventions and rules are the primary defaults where location matters.
Is data sent to a server?
No. The calculation runs locally in the browser and does not send entered values to a remote calculation service.