UK vs US bra sizes: the band numbers are generally the same, but the cup letters can be different. For example, a UK F cup is commonly equivalent to a US G cup.
Bra brands do not all use the same cup lettering, so always check which sizing system the brand uses when comparing UK and US bra sizes.
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UK and US bra sizing can be confusing because, although the band sizes are generally the same, the cup letter sequence is different. This means the same cup volume may have a different letter depending on whether the bra uses UK or US sizing.
If you are unsure of your starting size, check your measurements first using our Bra Size Calculator. You can then use this guide to compare UK and US cup sizes before buying a bra.
UK and US bra sizing both use the difference between the band and fullest bust measurements to determine the cup size. The main difference is the letters used to label the cup sizes.
UK sizing includes double letters such as DD, FF, GG, HH and JJ. US sizing usually follows a different sequence after D or DD and may use DDD instead of the UK E cup before continuing through single letters.
UK and US bra sizes begin with the same cup letters, but the sequence starts to differ after D. This means the same cup volume can have a different letter depending on which sizing system is used.
D, DD, E, F, FF, G, GG, H, HH, J, JJ, K, KK, L, LL
D, DD, DDD/F, G, H, I, J, K, L, M, N, O
The US sequence shown above is commonly used for international size conversions, but not every American lingerie brand follows exactly the same cup lettering.
For example, a UK H cup is commonly equivalent to a US K cup. British brands such as Freya, Fantasie and Elomi use UK sizing as their main system but also publish US equivalents in their international size charts.
When buying a bra, always check whether the size shown by the brand or retailer uses UK or US cup lettering rather than relying on the cup letter alone.
The table below shows the common US equivalent for UK bra cup sizes. The band size normally stays the same, so for example a UK 34F is commonly equivalent to a US 34G.
Bra brands do not all use the same cup lettering, so use this as a general UK to US conversion rather than assuming every brand will show the US equivalent on its label.
| UK Cup Size | Common US Equivalent |
|---|---|
| D | D |
| DD | DD |
| E | DDD/F |
| F | G |
| FF | H |
| G | I |
| GG | J |
| H | K |
| HH | L |
| J | M |
| JJ | N |
| K | O |
Conversion source: Our UK to US cup size comparisons are based on international size charts published by Wacoal Europe brands, including Freya, Fantasie, Elomi and Goddess. See the Freya International Size Guide .
British lingerie brands such as Freya, Fantasie and Elomi use UK cup sizing as their main sizing system. However, their official international size charts also show equivalent US cup sizes, which can have different letters.
For example, a UK 34E is equivalent to a US 34DDD on these brands' conversion charts. When buying a bra, check whether the brand or retailer is displaying the UK size or its US equivalent before ordering.
For brand-specific sizing information, see our Bra Brand Size Guides .
The example below shows how a UK 34E converts across different international sizing systems. In US/CA sizing, the equivalent is 34DDD/F – the band stays the same, but the cup lettering changes.
UK and US bra band sizes generally use the same numbers, such as 30, 32, 34, 36, 38 and 40. This means a UK 34 band is generally the same band size as a US 34 band.
However, fit can vary between brands and styles, so always check how the band fits rather than relying on the size on the label alone.
When buying a bra from a UK or US brand, check which sizing system is being used before converting your size.
For brand-specific sizing information, visit our Bra Brand Size Guides .
Is a UK H cup the same as a US H cup?
No. In a common UK-to-US conversion, a
UK H cup is equivalent to a US K cup.
British brands such as Freya, Fantasie and Elomi
use UK cup sizing but also publish US equivalents
in their international size charts. Always check
which sizing system the brand or retailer is using.
Why do UK bras use double letters like FF and GG?
UK bra sizing includes double letters such as
DD, FF, GG, HH and JJ
as separate cup sizes. This is why the UK cup
sequence differs from the common US sequence
as cup sizes increase.
Do UK and US band sizes differ?
UK and US band numbers are generally the same,
so a UK 34 band is also a US 34 band.
The main difference between the two sizing
systems is the cup lettering.
What is the US equivalent of a UK GG cup?
A UK GG cup is commonly equivalent to a US J cup.
However, brands may display UK or converted US
cup labels, so always check the manufacturer's
size chart before ordering.
Is an FF cup bigger than an F cup?
Yes. In UK sizing, an
FF cup is one cup size larger than an F cup
on the same band size. The UK sequence runs
F, FF, G, GG, so FF is the next cup size after F.
If you need more help understanding bra sizes, these guides explain cup sizing, size conversions and how bra sizes compare between brands.
