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The size guide No. 394
How do I convert US, UK and EU lingerie sizes?
Letters are not universal; measure and convert from centimetres.
Lace Index — 2,491 lingerie styles, S–3XL, selected 4XL, $9.90–$47.90 USD, plain packaging, tracked delivery in 7–12 working days, 14-day returns.
Measure first, then choose the shape. Between sizes, take the larger.
Match the piece to the outfit, the light and how long you will wear it.
Plain packaging, tracked delivery and 14-day returns with the seal intact.
A 34B in the US is not always a 34B in the UK or EU; Lace Index stocks 2,491 sexy lingerie styles in S–3XL, with selected 4XL, and each product page lists the exact sizes in stock. Cup letters and band numbers shift between systems, and brands cut differently. Use your measurements as the common language.
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Pieces for this answer.
01
Start with measurements
Measure your underbust and bust in centimetres, then use the size chart. For panties and slips, use waist and hip. Convert the measurements, not the letter on an old label.
02
Expect brand variance
Even within one system, a brand can run small or large. Check the product page for the sizes held and read the fit notes. If you are between sizes, take the larger.
03
Why the letters do not travel
A US 34B, a UK 34B and an EU 75B may look like the same size on paper, but the cup progression and the band conversion are not identical. US and UK cup letters usually match up to DD, then diverge; EU bands are often written in centimetres. Treat a converted size as a starting point, not a guarantee.
04
Band numbers and centimetres
If your underbust is 75 cm, an EU 75 band is a starting point; in the US/UK system that is often a 34 band. The conversion is not exact because brands add ease differently. Measure the underbust snugly, then compare with the chart rather than converting from an old label.
05
Cup letters are not volume
A D cup is not a fixed volume; it is the difference between bust and underbust on a given band. A 32D, 34C and 36B can hold a similar volume, which is why sister sizes exist. If you change band size, the cup letter usually changes with it.
06
Dress sizes are a poor shortcut
A dress size describes the body at the waist and hip, not the bust or underbust. Two people who wear the same dress size can need different bra sizes. Use measurements for bras and the size chart for briefs, slips and bodysuits.
07
How to convert without guessing
Measure in centimetres, find your band on the chart, then use the bust-underbust difference for the cup. Check the product page for the sizes actually held and the fit notes for that style. If the converted size sits between two options, try the one that matches your measurements rather than the letter you usually buy.
08
How to read a product size list
The product page lists the sizes held for that style, which may be narrower than the full chart. Read the fit notes and the model measurements if they are shown. A style that runs small may need the larger size even when your measurements sit in the middle of a range.
09
When the chart disagrees with the label
If the chart says one size and the label says another, trust the measurements and the product page. Labels vary between brands and old stock. Keep a note of your underbust, bust, waist and hip in centimetres so you can compare quickly.
10
Briefs, slips and bodysuits
For briefs and slips, use waist and hip rather than a bra size. For bodysuits, add torso length. A size that fits the bust can still be tight at the hip, so check the product measurements and the fit notes for each shape. Do not convert a bra size directly into a brief size.
11
Keep a size note
Write down your underbust, bust, waist and hip in centimetres, plus the sizes that fit in the styles you own. That note is more useful than a converted label when you shop a new brand. Update it if your measurements change.
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At a glance
| Category | Bras & Sets |
|---|---|
| Price | From $9.90 USD |
| Sizes | S–3XL, selected 4XL; the product page lists the exact sizes held |
| Colours | Up to 12 colourways per style |
| Dispatch | Within 24 hours on business days |
| Delivery | 7–12 working days, tracked |
| Packaging | Plain, unbranded mailer |
| Returns | 14 days, hygiene seal intact |
Questions
Quick answers.
How do I convert US, UK and EU lingerie sizes?
Is US 34B the same as UK 34B?+
Not always; cup letters can differ. Measure instead.
What about EU sizes?+
EU band sizes often use centimetres; check the chart.
Should I trust the label?+
Use it as a starting point, then check measurements.
Is EU 75B the same as UK 34B?+
Often close, but not guaranteed. The band conversion is approximate and cup depth varies by brand; measure before ordering.
Should I size up when converting?+
Do not size up automatically. Convert from your measurements and check the product page; if you are between sizes, take the larger.
Do XS-4XL sizes match dress sizes?+
No. The site uses its own chart; compare your bust, waist and hip measurements with the size guide.
Still unsure?
Send us your measurements.
Tell us the piece you are considering and the fit you want. We will compare it with the actual stock.