Size is the number one cause of lingerie returns, and almost always for the same reason: people buy by habit («I have always been a 90B») instead of by measurement. Ten minutes with a tape measure saves weeks of returns.
How to measure yourself in three steps
You need a flexible tape measure and, ideally, an unpadded bra or none at all. Measure standing up, relaxed and breathing normally.
- Underbust. Tape snug directly under the bust, horizontal and parallel to the floor. This number sets the band size (30, 32, 34, 36…).
- Bust. Tape across the fullest part of the bust, without pulling tight. It must stay horizontal across your back too.
- Subtract. Bust minus underbust. The difference gives you the cup.
| Difference (cm) | Cup (European system) |
|---|---|
| 10-12 | A |
| 12-14 | B |
| 14-16 | C |
| 16-18 | D |
| 18-20 | E (DD) |
| 20-22 | F |
| 22-24 | G |
Equivalents between sizing systems
The three systems you will meet most often in online shops are continental European (Spain, Italy, Germany), French/Belgian numbering, and UK/US. This table covers the central range; for larger cups the systems diverge and you should check the brand’s own chart.
| Underbust (cm) | ES / IT / DE | FR / BE | UK / US |
|---|---|---|---|
| 63-67 | 65 | 80 | 30 |
| 68-72 | 70 | 85 | 32 |
| 73-77 | 75 | 90 | 34 |
| 78-82 | 80 | 95 | 36 |
| 83-87 | 85 | 100 | 38 |
| 88-92 | 90 | 105 | 40 |
| 93-97 | 95 | 110 | 42 |
On cups, the British system adds double letters (DD, E, FF…) where the continental one uses a single letter. A European E cup is roughly a British DD, not a British E: that is the most common conversion mistake.
How to tell whether a bra fits
- The band should sit horizontal and firm on the loosest hook, leaving two positions of room as the fabric relaxes.
- The underwire encircles the breast tissue without resting on it or digging into the armpit.
- The centre gore touches the sternum. If it stands away, the cup is too small.
- The straps provide at most 10 % of the support. If you have to tighten them hard, the band is too big.
- No wrinkling in the cup (cup too big) and no spillage over the top or side (cup too small).
Fabrics: what to expect from each
| Fabric | Feel and drape | Breathability | Care |
|---|---|---|---|
| Cotton | Matte, soft, little stretch without elastane | High | Normal wash; shrinks with heat |
| Microfibre (polyamide/polyester) | Smooth, invisible under clothes | Medium-low | Very durable; dries fast |
| Polyamide lace | Stiff or soft depending on weight; can scratch | High by design | Wash bag essential |
| Tulle / stretch mesh | Very light, moulds to the body | High | Fragile: snags easily |
| Silk | Fluid, cool, natural sheen | High | Hand wash or dry clean; stains with deodorant |
| Polyester satin | Silk-like sheen, heavier | Low | Easy to wash; holds odour |
| Modal / viscose | Very soft, fluid drape | High | Distorts if wrung out wet |
Elastane (spandex, Lycra) appears in almost everything at 5-20 %. The more elastane, the better the garment moulds… and the sooner it deforms with heat. That is the main reason a piece «gives» after three months.
Care that makes garments last
- Wash at 30 °C or below, always in a mesh bag and with the hooks fastened.
- No tumble dryer: heat destroys elastane and permanently warps underwires.
- Do not wring. Press with a towel and dry flat in the shade.
- Store underwired bras stacked, not folded in half: folding the cup deforms it.
- Rotate pieces. Wearing the same bra two days running gives the elastic no time to recover.
Frequently asked questions
How often should I re-measure?
At least once a year, and always after a weight change, a pregnancy or a hormonal shift. Your size is not a lifetime constant.
My size varies between brands — is that normal?
Completely. There is no binding international sizing standard for lingerie: every brand uses its own block. That is why you should buy from the product’s measurement chart, not from the letter.
Which fabric is best for everyday wear?
For everyday, cotton or modal with a little elastane: they breathe, survive frequent washing and do not irritate. Lace and satin perform better in occasional use.
With sizing sorted, the next step is cut: we cover it in how to choose lingerie for your body.