FAQ
Bra Size and Fit Questions
Direct answers about calculator results, measuring, sister sizes, international conversion, fit problems, breast shape and privacy.
Calculator How Accurate Is the Bra Size Calculator?
The calculator gives a well-reasoned starting size based on your measurements, not a guaranteed final fit. Construction, fabric, and brand all affect how a labelled size actually feels. Use the result as your first size to try, and the Fit Checker to confirm it.
Calculator Should I Use the Quick or the Advanced Calculator?
The quick calculator needs only two measurements and gives a fast estimate. The advanced calculator asks for six measurements (three underbust, three bust) and produces a tighter, more reliable starting range. Use it if the quick result surprises you.
Calculator Why Does My Result Look So Different From the Size I Currently Wear?
A smaller band paired with a larger cup letter is common and does not mean the result is wrong, since cup letters are relative to band size, so the same cup volume carries a different letter on a different band. Read our guide on why the calculated size may look wrong for a full explanation.
Calculator What if My Measurements Fall Between Two Sizes?
Try the closest calculated size first. If it's genuinely borderline, the Sister Size Calculator can show you the nearest alternatives with a similar cup volume.
Calculator Should I Measure With a Bra On?
Measure the underbust without a bra, or in an unpadded one, so the tape reads your actual ribcage. Measure the bust without a padded or moulded bra too, since padding adds volume the calculator would otherwise count as yours.
Privacy Do You Store or Send My Measurements Anywhere?
No. Every calculation runs in your browser. Your measurements are never transmitted to a server, logged, or saved. Closing or refreshing the page clears them.
Privacy Do I Need to Create an Account to Use the Tools?
No account, email, or sign-up is required for any calculator on this site.
Privacy Are My Measurements Stored on This Device?
Not unless you explicitly choose to save them on this device. Measurements stay in your browser during a calculation and are never sent to our servers or included in analytics.
Privacy How Can I Delete Saved Measurements?
If you've saved a result on this device, a delete option is available wherever it's shown. Clearing your browser's local storage for this site also removes anything saved here.
Sizing Systems Which Countries and Sizing Systems Are Supported?
UK, US, EU, France/Belgium/Spain, Australia/New Zealand, and Japan. Use the International Converter to move a size between any of these systems.
Sizing Systems Why Do UK and US Sizes Disagree Past a D Cup?
UK and US cup letters match up to D, then diverge, since the US market has no single agreed label for the position after D, so brands use DD, DDD, E, or F for the same cup volume depending on the brand.
Sizing Systems Why Does a D Cup Look Different on Different Bands?
Because a cup letter describes a volume relative to the band, not an absolute size. A 30D and a 38D carry very different amounts of tissue despite sharing a letter, since the band number is what makes the letter meaningful.
Fit The Calculated Size Does Not Fit One Bra I Own, Is the Calculator Wrong?
Not necessarily. A calculator cannot see cup depth, wire width, or fabric stretch, so a construction-specific issue can make an otherwise-correct size feel wrong in one particular style. Use the Fit Checker on that specific bra to see what is actually happening.
Fit What's the Difference Between the Fit Checker and the Size Calculators?
The size calculators estimate a starting size from measurements. The Fit Checker instead evaluates a bra you already own, covering band, cups, wires, gore, and straps, to diagnose what is or isn't working about that specific garment.
Fit Are Sister Sizes Identical?
No, they share an approximate cup volume, not an identical fit. Band tension, strap position and wire geometry all change with the band size, so a sister size is worth trying, not assuming will fit exactly the same.
Fit Can Gaping Mean the Cup Is Too Small?
Usually not directly. Gaping more often points to excess volume or a shape mismatch than to a cup being too small. It can still be worth testing a smaller cup, but the band-only test and cup shape are better first signals than assuming it's a straightforward size issue.
Fit Can Breast Shape Change the Size I Need?
Shape doesn't change your measurement-based starting size, but it does change which cup construction actually contains that volume comfortably. Two people with the same size can need very different cup shapes.
Brands Will My Calculated Size Be the Same at Every Brand?
Not guaranteed. Brands publish their own size guides and use different constructions, so the same label can fit differently across brands. Use Brand Size Match to translate a size you know into other supported brands.
Brands What Does "Verified" Mean Next to a Brand Result?
It means that brand's own published size guide directly confirms the label shown. Unverified or partial matches are marked accordingly, and we recommend checking the brand's official chart before ordering.
Brands Why Do Brands Use Different Labels?
Past a D cup, the US market in particular has no single agreed cup-letter sequence, so different brands use DD, DDD, E or F for the same relative volume. Our converter shows a common label and flags the accepted alternative rather than picking one as definitively correct.
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