Bra Size Conversion Explained: UK, US, and EU Systems
A bra labelled 34E in the UK may appear as 34DDD in a US size selector and 75F on an EU chart. Those labels can describe corresponding sizes, but the conversion depends on the brand’s sizing conventions. Understanding band numbers and cup letters separately makes bra size conversion easier—and helps you spot when a retailer’s chart needs a closer look.
What the number and letter mean
A bra size has two connected parts:
- The band number identifies the size of the band around your torso.
- The cup letter identifies the cup size relative to that band.
The letter alone does not describe a fixed volume. Within the same sizing system and range, a 36D generally has more cup volume than a 32D.
When comparing UK US EU bra sizes, convert both parts of the label. Keeping the cup letter unchanged works for some sizes, but becomes unreliable once the systems’ lettering sequences diverge.
Band size conversion: UK, US, and EU
UK and US bras commonly use the same band numbers, increasing in steps of two: 30, 32, 34, and so on. EU band labels use a centimetre-based system, usually increasing in steps of five.
The following table shows common label conversions.
| UK band | US band | EU band |
|---|---|---|
| 28 | 28 | 60 |
| 30 | 30 | 65 |
| 32 | 32 | 70 |
| 34 | 34 | 75 |
| 36 | 36 | 80 |
| 38 | 38 | 85 |
| 40 | 40 | 90 |
| 42 | 42 | 95 |
| 44 | 44 | 100 |
| 46 | 46 | 105 |
This is a label conversion table, not a body measurement chart. A UK 34 commonly converts to an EU 75; multiplying 34 by 2.54 will not produce its EU label.
If you are choosing a size from fresh measurements, follow the brand’s measuring instructions instead of treating this table as a sizing calculator.
Also check the regional heading carefully. French band labels differ from EU labels: an EU 75 commonly appears as a French 90. A size described simply as “European” may therefore need clarification.
Cup size conversion: where the letters change
The familiar A, B, C, and D labels generally line up in conventional conversion charts. After D, the sequences become more complicated.
UK sizing commonly progresses through D, DD, E, F, FF, G, GG, H. EU sizing typically uses single letters: D, E, F, G, H, I, J, K.
US sizing varies between brands. A common sequence is D, DD, DDD, G, H, I, J, K, while some brands use E for DD or F for DDD.
Common cup label reference table
Use this table as a starting point, alongside the band conversion above.
| UK cup | Common US cup label* | Common EU conversion label |
|---|---|---|
| AA | AA | AA |
| A | A | A |
| B | B | B |
| C | C | C |
| D | D | D |
| DD | DD or E | E |
| E | DDD or F | F |
| F | G | G |
| FF | H | H |
| G | I | I |
| GG | J | J |
| H | K | K |
| HH | L | L |
| J | M | M |
| JJ | N | N |
US alternatives depend on the manufacturer. An E or F label should always be checked against that brand’s chart.
These are common commercial conversions, rather than guarantees of identical cup dimensions. In particular, a UK G and a US G usually occupy different positions in their respective sequences.
Worked bra size conversion examples
UK 34E to US and EU
Start with the band: UK 34 commonly corresponds to US 34 and EU 75.
Next, convert the cup: UK E commonly corresponds to US DDD, sometimes labelled F, and EU F.
Your starting sizes are therefore US 34DDD or 34F, depending on the brand, and EU 75F.
US 36DD to UK and EU
The band remains 36 for UK sizing and becomes 80 for EU sizing.
In the common sequence shown above, US DD corresponds to UK DD and EU E.
That gives UK 36DD and EU 80E as starting points.
EU 70H to UK and US
EU 70 commonly corresponds to a UK or US 32 band.
Using the reference table, EU H corresponds to UK FF and commonly US H.
The resulting starting sizes are UK 32FF and US 32H. Confirm that the particular EU brand follows this conversion before ordering.
Why the brand’s size chart takes priority
A conversion chart translates labels, but manufacturers do not all build cups to the same measurements. Traditional UK and US cup grading commonly uses one-inch increments, while standard EU grading uses two-centimetre increments. Those steps are different, so matching positions in a lettering sequence does not ensure matching dimensions. The overview of international bra sizing systems explains these differences and the variation between manufacturers.
Style matters too. Cup depth, wire width, padding, and fabric stretch can change how a bra fits even when its label matches a size you already wear.
Before ordering:
- Confirm the size selector’s system. A retailer selling an imported bra may display the brand’s original sizing.
- Open the chart for that brand or product range. Check whether it provides international conversions, measurement guidance, or both.
- Convert from a clearly identified size. “UK 34E” is more useful than “34E” without a regional label.
- Read any style-specific fit notes and the return policy. Leave yourself room to assess the garment’s actual comfort and support.
Conversion and sister sizing serve different purposes
International conversion translates a size into another system. Sister sizing changes the band while keeping cup volume approximately similar within a sizing system.
For example, the UK sister sizes around 34E are 32F and 36DD. These offer different band fits; they are not international versions of 34E.
Once your bra arrives, check that the band stays level, the cups contain your breast tissue comfortably, and any underwires avoid pressing on breast tissue. Move, sit, and raise your arms. A converted label is a useful starting point, but comfortable fit is the deciding factor.