Every size on this site is explained the same way: what it means, what it’s equivalent to elsewhere, and what fit problems tend to show up at that size.
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What’s In This Section
Full band-and-cup charts across all 7 sizing systems, individual guides for the most commonly searched sizes, and visual references for what cup volume actually looks like at each letter. None of this replaces measuring your own body — it’s here to help you understand a result once you have one, or sanity-check a size you’re considering buying.
Start With These
If you already have a size in mind, jump straight to the Size Charts for the full conversion table, or Cup Size Visuals if you want to see how cup letters actually compare to each other rather than just read the labels.
How to Read a Size Chart Correctly
A size chart lists band and cup as two separate numbers because they measure two different things: the band measures your ribcage circumference, the cup measures the volume difference between your underbust and bust. Reading a chart correctly means finding your band row first, then your cup column — not searching for a single combined number, since the same cup letter means a different volume depending on which band it’s paired with.
This is also why comparing sizes across a chart sideways works: two sizes in the same diagonal line (band up 2, cup down 1, or the reverse) are sister sizes holding the same volume — see the comparison guides linked throughout this section for specific pairs.
Individual Size Guides
What’s Covered Here
This hub links to individual size guides spanning small bands (28″) through large bands (42″), and cup letters from AA through the fuller end of the range — each with its own sister sizes, international conversions, and fit tips specific to that exact combination.
Don’t See Your Exact Size?
Between the individual size guides and the size comparison pages, most band-and-cup combinations that actually show up in real measurements are covered. If yours genuinely isn’t listed, the Main Bra Calculator still gives you an accurate size — the individual guide pages are a deeper reference, not a requirement for getting your size.
Rare vs. Common Sizes
Some combinations on this list are far more common than others — mid-range bands paired with mid-range cups are the most heavily stocked in stores, while extreme bands or cup letters are real, valid sizes that are simply harder to find on a typical retail floor. Each guide is honest about which category it falls into.
How to Use This Hub If You Don’t Know Your Size Yet
Start with the Main Bra Calculator to get your actual size first — the guides linked from this hub are most useful once you have a specific band and cup to look up, rather than browsing sizes without a starting reference point.
What’s Different Between a Size Guide and a Size Chart
A size chart (see Bra Size Charts) shows the full conversion table across systems at a glance. An individual size guide goes deeper on one specific size — sister sizes, fit tips, and what that particular band-and-cup combination actually looks and feels like.
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Frequently Asked Questions
No — start with the Main Bra Calculator if you don't have a size yet, then come back here to understand what the result means or compare it to other sizes.
No single chart is universal — brands vary by half a size or more in cut and construction. These charts describe the standard convention, not any one retailer's exact fit.
A size chart shows the full conversion table across systems. A size guide focuses on one specific size — what it means, its sister sizes, and common fit notes.
We've covered the most commonly searched sizes in depth first. If yours isn't listed yet, the Size Charts page still covers the full range.
Just your own size guide is genuinely useful — the guides are written per-size specifically so you don't need to read unrelated ones.
Check the Bra Size Charts page for the full conversion table, or use the Main Bra Calculator directly — coverage is broad but a few extreme combinations may not have a dedicated guide yet.
Sizing conventions themselves are stable, so the core guidance doesn't need frequent changes — the underlying math matches the site's calculators at all times.