Bra fit diagnosis

Tick the problems you have with your current bra. You’ll get a specific UK size to try next, what’s causing each problem, and a clear note if your problems point in opposite directions.

How the diagnosis works

Each fit problem points to something specific: a band that is too loose, cups that are too small, wires that are the wrong shape for you. The tool looks at your problems together, because real fit problems usually come in combinations.

When two problems point in opposite directions, such as a band that rides up and digs in, the tool says so instead of averaging them out. That combination usually means the band’s shape or depth is wrong rather than its size, and a change of style will help more than a change of size.

What is sent

Only the problems you tick, the sizes you choose, your breast shape if you pick one, and your note with numbers removed. Your measurements are never sent, and we don’t store requests or answers. See the privacy page for details.

When to see someone

This tool helps with fit. It doesn’t diagnose medical problems. If you have numbness, skin damage, a lump, or pain that doesn’t ease in a well-fitting bra, please see your GP.

Frequently asked questions

Some combinations point in opposite directions. A band that rides up suggests a smaller band, while a band that digs in suggests a bigger one. When both happen, the band’s shape or depth is usually the issue, so the tool names the contradiction and suggests a style change rather than averaging the two into a size that fixes neither.

Yes. You always get one specific UK size to try next, plus alternatives. Sometimes that size is the one you already wear, with a different style, because the problem is shape rather than size.

No. We don’t store your request or the answer. Numbers are removed from your note before it’s sent, except bra sizes. The note is processed by our AI provider to write your answer; the privacy page explains exactly what is sent.

No. It helps with fit only. If you mention numbness, skin damage, a lump or pain that doesn’t ease, it will suggest seeing your GP rather than offering a size change as the fix.

Explainer guides

Bra fit problems

What causes each fit problem, and the fix.

How to tell if your bra fits

A step-by-step fit check for the fitting room.

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Sophie Dixon

Sophie Dixon

Hi, I’m Sophie Dixon, the creator of UK Bra Size Calculator. I built this tool because I was tired of seeing women guess their bra size from outdated charts that rarely fit right. I researched UK bra fitting standards and measurement methods in depth so I could offer both the modern and traditional sizing approaches side by side – giving you an honest comparison instead of a single guess. Everything runs privately in your browser, and I’m always refining the calculator to make it more accurate.