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Bra Size Calculator — Find Your True Bra Size
Calculate your bra size free using our accurate bra size calculator. Enter your measurements to find band size, cup size, and sister sizes. Use the interactive bra size calculator below to get a fast browser-based result without creating an account.
Use the controls below. The widget loads automatically when this tool page opens.
How Do You Calculate Bra Size?
Measure your band under the bust and your bust at the fullest point. Round the band to an even number, then use the difference for cup size.
How to Use Bra Size Calculator
- 1Open the widget
Use the Bra Size Calculator controls at the top of this page.
- 2Enter your input
Enter the measurements, quantities or settings requested by Bra Size Calculator, then review the calculated total.
- 3Run and review
Review the bra size calculator result, compare the supporting details, then change the inputs to test another scenario.
About bra size calculator
Bra Size Calculator focuses on bra size calculator and related needs such as bra size calculator, bra size guide, how to measure bra size, bra fitting calculator. The interactive widget appears before the long explanation so search visitors can solve the task first, then read the supporting notes if they need context.
Bra Size Calculator estimates everyday home, hobby or reference values from your inputs. It works best when you measure carefully and include a practical margin for real-world variation.
For best results, start with clean inputs, run the tool once, then review the supporting details before using the output. If the result affects money, health, publishing, legal work or a public file, verify the final answer with another trusted source.
Frequently Asked Questions
How do I measure my bra size at home?
Measure the band directly under the bust and the bust at the fullest point. Keep the tape level, snug but not tight, and measure in a relaxed standing posture.
What are sister sizes in bras?
Sister sizes keep a similar cup volume by moving one band size down and one cup size up, or one band size up and one cup size down. For example, 34C is close to 32D and 36B.
Why does bra sizing differ between brands?
Bra sizing differs between brands because cup shapes, band stretch, materials and regional size systems vary. Treat the calculator result as a starting point and check the actual fit.
How should a bra fit?
A good fit has a level snug band, smooth cups without spilling or gaping, a center gore that rests flat and straps that support without digging into the shoulders.