The fix: go down one band size and up one cup letter. A 36C becomes a 34D, and a 34DD becomes a 32E. The cup holds the same volume and the band is firm enough to stay level.
Why a loose band rides up
Think of the bra as a seesaw balanced on your sides. Your breasts put weight on the front. If the band grips your ribcage firmly, that weight is spread around your body and the band stays level. If the band is loose, nothing resists the weight, so the front tips down and the back swings up.
Most people respond by shortening the straps to lift the front again. That hauls the back of the band up even further and moves the load onto the shoulders. If your band rides up and your straps dig in, this is why.
Confirm it in thirty seconds
- Mirror check. Stand side-on. The band should be level with the floor. Higher at the back means it is too loose.
- Pull check. Pull the band away from your spine. More than about two inches of slack is too much.
- Hook check. If you are on the tightest hook and it is still loose, the band is too big or worn out.
- Arms-up check. Raise your arms. If the band lifts and your breasts slip out beneath the cups, there is not enough grip.
The fix: band down, cup up
Dropping the band alone would also shrink the cups, because cup letters are relative to the band. To keep the cups the same size, go up one letter as you go down one band. This pairing is called a sister size.
| If you wear | Try | If you wear | Try |
|---|---|---|---|
| 34B | 32C | 36D | 34DD |
| 34C | 32D | 36DD | 34E |
| 36C | 34D | 38D | 36DD |
| 34D | 32DD | 38DD | 36E |
These use UK cup lettering, where DD is followed by E. For any other size, use the sister size calculator.
If the band is very loose, with several inches of slack, you may need to go down two bands and up two cups. In that case it is more reliable to re-measure than to guess.
Check the cups while you are there
A band that is too big very often comes with cups that are too small. The two tend to arrive together when a size has been worked out by adding inches to the underbust, a method that inflates the band and shrinks the cup. See why the +4 method is wrong. If the size came from a high-street fitting, our guide to M&S sizing explains how to check it.
So when you try the new size, look at the cups as well. If you are bulging over the top or the centre panel will not sit flat, go up another cup letter on the new band. See spilling out of your bra cups.
Other causes to rule out
The bra is worn out
Elastic stretches. A bra that fitted well a year ago can ride up now because its band has lengthened. If moving to the tightest hook no longer helps, it needs replacing, in the same size if your body has not changed. See how often to replace your bras.
The straps are too short
Straps adjusted very tight will pull a correct band upwards. Loosen them until two fingers fit underneath and see whether the band settles.
The cups are too small
Occasionally the band is fine but undersized cups make the bra sit too high at the front and tilt at the back. If the band passes the pull check and still rides up, try a cup size up on the same band.
Your shape tapers sharply
If your ribcage narrows a good deal below the bust, bands tend to slide to the narrowest point. A style with a wider band and three or four rows of hooks holds its position better than a narrow one.
What the right band feels like
Firmer than you are used to, level all the way round, and still on the loosest hook. You should be able to slip two fingers underneath and breathe freely. Give a new, firmer band a few days before you judge it. How tight a bra band should be has the full set of tests.
Frequently asked questions
Should I tighten my straps to stop my bra riding up?
No. Tighter straps pull the back of the band higher. Loosen them slightly, pull the band down to sit level, and if it will not stay there, the band is too big.
Why does my bra ride up even on the tightest hook?
The band is too long for your ribcage, either because it is the wrong size or because the elastic has worn out. A smaller band, with a cup letter up to keep the same volume, is the fix.
Will a smaller band feel too tight?
It will feel firmer, and that takes a few days to get used to. It should not hurt. If the smaller band is painful, check that you also went up a cup letter, because cups that are too small make any band feel tight.
Find the firmer band with the same cup volume.
Open the sister size calculator →