Bra Fit Guide
Seven checks that tell you whether a bra actually fits, and what to change when one fails.
A calculator gives you a size to try. This page tells you whether it worked. Run these seven checks in a fitting room or at home with the tags still on. If one fails, the fix is usually a single step in band or cup – not a different brand and not a different body.
Before you check anything: scoop and swoop
Put the bra on, then lean forward and, with the opposite hand, sweep the breast tissue from under your arm and from the ribcage into the cup. Repeat on the other side. A surprising amount of what looks like a bad fit is tissue that was never in the cup to begin with. Do this every time before judging a size.
1. The band, on the loosest hook
New bras should fit on the loosest hook, so the tighter hooks are there as the elastic relaxes over the months. The band should sit level all the way round and stay put when you raise your arms. You should be able to pull it about 2 cm away from your back, and no further.
If it rides up or you can pull it far out: go down a band and up a cup. Full guide to a band that rides up.
2. The cup edge lies flat
The top edge of the cup should sit against your body with no gap and no cutting. Gaping at the top usually means the cup is too large for the shape, or the style is wrong for you.
If it gapes: try a cup down, or a style with more stretch at the upper edge. Full guide to cup gaping.
3. Nothing spills over
Tissue rising over the top edge or bulging at the underarm means the cup is not big enough to hold what you are asking it to hold – even if the number on the label sounds large.
If it spills: go up a cup, keeping the band the same. Full guide to spillage.
4. The underwire follows the root of the breast
The wire should sit on the ribcage, tracing the crease where breast tissue meets your body, and finish behind the breast at the underarm – never on top of tissue.
If it sits on tissue or pokes: the cup is usually too small or the wire too narrow. Full guide to wires digging in.
5. The centre panel sits flat
On most wired styles, the panel between the cups should touch the sternum. A floating gore is the clearest single indicator that the cup is too small – the cup is pulling the panel away from the body to make room.
If it floats: go up a cup first. If it still floats at two cups up, the style is wrong for your breast shape rather than your size.
6. The straps carry a little, not a lot
Straps take roughly 10 to 20 per cent of the load. The band does the rest. Straps that dig grooves into the shoulders are compensating for a band that is too loose.
If they slip: shorten them first; if they still slip when short, the band or cup is wrong. Full guide to slipping straps.
7. It holds through movement
Raise your arms above your head, twist, bend forward and walk. The band should not ride up, the cup should not release tissue, and the wire should not shift. A bra that fits standing still but fails this test does not fit.
Which change to make
| Symptom | Most likely change | Then try |
|---|---|---|
| Band rides up at the back | Down one band, up one cup | Down two bands if still loose |
| Tissue over the top edge | Up one cup, same band | A style with more coverage |
| Cup gapes at the top | Down one cup, same band | A stretch-lace or moulded upper edge |
| Centre panel floats | Up one cup | A different wire width |
| Wire sits on breast tissue | Up one cup | A wider wire style |
| Straps dig into shoulders | Down one band, up one cup | Wider straps |
| Straps slip off | Shorten straps | Down one band, or a leotard back |
Sizes are a starting point, not a verdict
Two bras labelled the same size can fit completely differently. If a size fails every check in one brand and works in another, that is normal and it is the brand’s grading, not your measuring.