A free online bra size calculator that computes your band and cup size from underbust and bust measurements in inches or centimeters. Converts to US, UK, EU, FR, and AU sizing systems. Includes a comprehensive size chart for reference. Uses standard bra sizing formulas for accurate results.
Select inches or centimeters.
Enter your underbust measurement.
Enter your bust measurement.
View your calculated size in US, UK, EU, FR, and AU.
Measure directly under your bust, keeping the tape snug but not tight. Ensure the tape is level around your torso.
The calculator rounds to the nearest even band size and finds the closest cup size. Try neighboring sizes for the best fit.
Free online tool — works in your browser, no sign-up required. Start using it right now.
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