Bra Size Calculator
Estimate US bra size from under-bust and bust measurements, with UK/EU conversions.
How to Use
- Measure under-bust (snug ribcage) and bust (fullest part).
- Result shows US/UK/EU band + cup sizes.
Show Work
Method
About the Bra Size Calculator
Whether you are at a desk or on your phone, the Bra Size Calculator makes everyday maths and number work easy — and it is completely free. Estimate US bra size from under-bust and bust measurements, with UK/EU conversions.
How it works
Type your numbers into the boxes. The answer shows up right away — you do not have to press a button. If you change a number, the answer changes too. So you can try different numbers and watch what happens, or check an answer you worked out yourself. Just make sure each box has the right kind of number in it.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How do I use the Bra Size Calculator?
Just type your numbers. The answer shows up right away — there is no button to press. Change anything and it updates by itself.
Is it free? Does it work without internet?
Yes to both. It is free with no sign-up, and once the page has loaded it keeps working even with no internet.
Where does my data go?
Nowhere — every calculation runs on your own device. Nothing you enter is uploaded, logged, or stored.
Common Use Cases
Try different numbers
Change one thing and watch the answer change. It is an easy way to compare your choices.
Nothing to set up
Open the page and start. There is nothing to install, and no account to make.
Check your work
Worked it out yourself? Use the Bra Size Calculator to make sure your answer is right.
Safe and private
Everything you type stays on your device. Nothing is sent to a server or saved.
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