Why your usual size often does not fit
The size on the label is a starting point, not a guarantee. Manufacturers cut differently, and even within one brand a balconette style fits differently from a full-cup bra. On top of that, the body changes: through weight fluctuations, sport, pregnancy, breastfeeding, hormonal changes or age. If you have bought the same size for years without checking it, you are quite likely wearing a bra that no longer fits optimally.
Typical signs are a band that rides up at the back, straps that dig in or keep slipping, cups that wrinkle or that the breast spills over, and underwires that press or stand away from the body.
A good bra goes unnoticed in daily life: it stays in place all day without pressing, slipping or needing constant adjustment.
Four points for a good fit
| Area | How it should be | Why it matters |
|---|---|---|
| Band | Sits horizontally and firmly, does not ride up when you raise your arms | Provides most of the support |
| Cups | Enclose the breast smoothly, without wrinkles or digging in at the edge | Prevents pressure marks and gives a smooth silhouette |
| Straps | Support without digging in or slipping | Should not carry the main load, otherwise shoulders hurt |
| Centre gore and underwires | Centre gore lies flat on the breastbone, wires fully encircle the breast | Improves shape, support and comfort |
A new bra should fit well on the loosest hook. That way you can tighten the band as it stretches over time.
How to get the fitting right
- Measure your underbust and bust as a guide, but do not rely on the numbers alone.
- Fasten the bra on the outermost hook and make sure the band sits horizontally.
- Lean forward slightly and settle the breast into the cups with your hand so that all tissue sits inside.
- Adjust the straps so that two fingers fit underneath.
- Raise your arms, sit down and turn: the bra should not shift.
- Put on a close-fitting top and check whether edges or seams show.
Tip
Try several styles and neighbouring sizes as well. Advice in a specialist shop can help, especially with larger cups, after a pregnancy or if you have not yet found a bra that fits.
Size systems and sister sizes
In Switzerland, European sizes such as 75B are the most common: the number stands for the underbust measurement, the letter for the cup size. French sizes are 15 higher in the number, so a 75 corresponds to a 90. British and American sizes use inches and partly different letter sequences; when buying online, check the manufacturer's size chart.
The principle of sister sizes is useful: cup volume depends on the band. If the band goes down one step, you need one letter more to keep the same volume. So 75B becomes 70C, and 80B becomes 75C. If the band is too loose but the cups fit, the sister size is often the solution.
Which bra for which purpose
| Style | Suits | Note |
|---|---|---|
| Moulded-cup bra | Everyday wear, smooth line under tops | Shape-retaining cups, discreet |
| Underwired bra | More support, especially with larger cups | Wires must fully encircle the breast |
| Wire-free bra or bralette | Comfort, smaller cups, at home | Less support but no pressure |
| Sports bra | Running, jumping, team sports | Choose the support level by the intensity of the sport |
| Nursing bra | Pregnancy and breastfeeding | Stretchy cups and easy opening |
On care: wash bras by hand if possible or in a laundry bag at a low temperature, avoid the tumble dryer and rotate several bras. This helps band and cups keep their shape for longer. When the band no longer holds even on the tightest hook, it is time for a replacement.