Size & fit guide · updated September 2026
Bra size conversion for Western markets — and how we grade it
A lingerie size run for the US, EU, UK and AU markets converts by band in centimetre steps, not by translating cup letters. This page gives the conversion tables we produce to, the measurement method we ask buyers to record, and the grade rules that decide whether a 42G fits or a 42G is a scaled-up 34B.
Table 1
Band conversion: US / AU ↔ EU ↔ UK
Band is derived from the underbust measurement. EU sizing is a centimetre range, so a US 32 legitimately covers EU 65 and 70 depending on the brand's fit intent.
| US / AU band | EU band | UK band | Underbust (cm) | Underbust (in) | Typical closure |
|---|---|---|---|---|---|
| 30 / 6 | 65 | 1 | 63–67 | 24.8–26.4 | 2-hook |
| 32 / 8 | 65–70 | 2 | 68–72 | 26.8–28.3 | 2–3 hook |
| 34 / 10 | 75 | 4 | 73–77 | 28.7–30.3 | 3-hook |
| 36 / 12 | 80 | 6 | 78–82 | 30.7–32.3 | 3-hook |
| 38 / 14 | 85 | 8 | 83–87 | 32.7–34.3 | 3–4 hook |
| 40 / 16 | 90 | 10 | 88–92 | 34.6–36.2 | 4-hook, side bone |
| 42 / 18 | 95 | 12 | 93–97 | 36.6–38.2 | 4-hook, side bone |
| Produced ranges: US 30A–42H · EU 60–95 · UK 1–12 · AU 6–20. Sister sizes (e.g. 34C ↔ 32D) share cup volume but not band support, so we do not substitute them in a bulk run. | |||||
Table 2
Cup conversion by bust minus underbust difference
Cup letters are system-specific because they are measured from different bases. Use the centimetre difference, then map it to your market's lettering.
| Difference (cm) | US / UK | EU / FR | AU | Production note |
|---|---|---|---|---|
| 10–12 | A | A | A | Single-layer lace or thin lining |
| 12–14 | B | B | B | Standard moulded or simplex cup |
| 14–16 | C | C | C | Add side support panel from 36C |
| 16–18 | D | D | D | Wire gauge step-up; deeper cup apex |
| 18–20 | DD / E | E | DD / E | US and UK diverge here — confirm your chart |
| 20–22 | DDD / E | F | F | Strap width 14–18 mm; 3-hook minimum |
| 22–25 | G | G | G | Re-blocked: higher wing, side boning |
| 25–28 | H | H | H | 4-hook, 20–25 mm strap, reinforced cradle |
| We produce to your market's chart (US, UK, EU or AU) and label accordingly; we never translate letters between systems without re-grading the cup. | ||||
Measurement method
What we ask buyers to record before grading
Step 1
Underbust, snug
Measuring tape level and firm against the skin, no bra, taken at the end of a normal exhale. Record in cm.
Step 2
Overbust, fullest point
Tape parallel to the floor across the apex without compressing tissue. Soft-tissue buyers should measure leaning forward.
Step 3
Derive band and cup
Band from underbust, cup from the difference. Note the depth of the apex, not just the letter.
Step 4
Fit session on your size set
We send a size set (3 sizes across your curve) and a comment sheet; changes are locked before the PP sample.
Sister sizes: 34C and 32D share roughly the same cup volume but not the same band support or cradle length. In a bulk run we produce the size you sell, never a sister-size substitute.
Panty & loungewear conversion
| Alpha | US | EU | UK | AU | Hip (cm) |
|---|---|---|---|---|---|
| XS | 0–2 | 32–34 | 4–6 | 6–8 | 81–86 |
| S | 4–6 | 36–38 | 8–10 | 10–12 | 87–93 |
| M | 8–10 | 40–42 | 12–14 | 14–16 | 94–101 |
| L | 12–14 | 44–46 | 16–18 | 18–20 | 102–109 |
| XL | 16 | 48 | 20 | 22 | 110–117 |
| 1X | 16W–18W | 48–50 | 20–22 | 22–24 | 118–127 |
| 2X | 18W–20W | 52–54 | 24–26 | 26–28 | 128–137 |
| 3X | 20W–24W | 56–58 | 28–30 | 30–32 | 138–148 |
| 4X | 24W–26W | 60–62 | 32–34 | 34–36 | 149–160 |
Extended blocks: from 1X and above, panel length, gusset width and elastic tension change — not just the circumference.
Fit tips for cross-border selling
Five things that reduce intimates returns
Publish the cm range, not just the letter
Buyers who see underbust centimetres on your product page return roughly a third less than those comparing letters across markets. We supply the cm table per style for your PDP.
Grade the strap and the closure with the size
A 40 band on a 34 strap digs. Above a 38 band we widen straps and add hooks as part of the block, not as an upsell.
Test the biggest size in your run first
Fit issues appear at the ends of the curve. Sample 3X / 42G before approving the block, then the middle sizes follow.
Match fabric stretch to the size tier
High-stretch lace that reads well in S will roll at the hem in 2X; we adjust elastic weight per tier and record it in the spec sheet.
Keep one chart across the capsule
If the bra, the brief and the robe use three different curves, the customer sizes up and returns the set. We build one master chart per program.
Size FAQ
Questions about sizing and grading
How do I convert a US bra size to EU?
Convert the band in centimetre steps — US 32 → EU 65–70, 34 → 75, 36 → 80, 38 → 85, 40 → 90, 42 → 95 — then confirm the cup by the overbust minus underbust difference in cm rather than translating the letter. A US D and an EU D are not the same volume because they sit on different bases.
How should a buyer measure for a size run?
Snug underbust (no bra, end of exhale) gives the band; overbust at the fullest point without compression gives the cup. Record both in cm per fit model and send us the sheet — that becomes the grade rules for your bulk order. Method detail above in Measurement method.
What range do you grade for plus size?
Bras US 32A–42H / EU 65–95 / UK 1–12; panties, bralettes, shapewear and loungewear XS–4X (AU 6–36). Above XL and above a 40 band the block is re-patterned — see Shapewear & Plus Size.
Can you produce to our existing brand size chart?
Yes. Send the chart you already sell and we will grade to it, flagging any size where the construction (wire, strap, closure) needs to change to keep the fit honest. A size set is produced for sign-off before bulk.
Related: Bras & Panty Sets · OEM / ODM development · Quality & Compliance
Get a size set for your curve
Send your chart and we will produce three sizes across it with a fit comment sheet — the fastest way to know if our grading matches your brand.