JJ Cup Bras – Brands That Make JJ Cups & How to Find Your Size
Finding supportive bras in a UK JJ cup can be extremely challenging. Many brands stop well before this cup size, and even among specialist fuller-bust brands, availability can be limited. This guide focuses specifically on JJ cup bras, explaining which brands make them, which band sizes are available, and how JJ sizing works across different UK cup sequences.
To confirm your starting size, begin with our Bra Size Calculator, then explore the specialist brands listed below.
Who This Guide Is For
- Women who wear a UK JJ cup
- Those sized out of high-street and mainstream brands
- Fuller-bust and fuller-figure customers
- Shoppers comparing extended UK cup sizing
- Anyone repeatedly sister-sized due to limited availability
Why Not All JJ Cup Bras Are the Same
Although JJ cup is a recognised UK bra size, the cup letter alone does not represent one fixed volume. Cup volume changes with band size, and some brands use different cup lettering systems when labelling equivalent measurements.
The JJ cup is part of the extended UK bra size sequence used by many fuller-bust brands. It sits between J and K, with each step representing a one-inch increase in the difference between the bust and underband measurements.
JJ cup sizes are commonly found in specialist lingerie brands that offer a wider range of cup sizes than standard high-street collections. As with all bra sizes, the combination of the band size and cup size determines the overall volume.
If you are comparing neighbouring cup sizes, see our J vs JJ vs K Cup Size Comparison guide.
You can also explore our How Big Are JJ Cups? guide to see how JJ cup volume changes across different band sizes.
How Big Is a JJ Cup?
A UK JJ cup bra sits within the fuller-bust end of the extended UK cup size sequence. However, how large a JJ cup appears depends on factors such as band size, body proportions and bra design.
For example, a 30JJ and a 40JJ do not have the same cup volume. Cup volume increases as band size increases, which is why the cup letter alone does not tell the full story.
If you would like to see visual examples across different band sizes, visit our How Big Are JJ Cups? guide.
JJ Cup Size Progression
A JJ cup sits between J and K in the extended UK cup size sequence used by many fuller-bust brands. The diagrams below show how cup volume increases gradually while the band size remains the same.
JJ sits between J and K in the UK bra size sequence.
These simplified educational diagrams show how cup volume increases across nearby UK cup sizes when the band size stays the same.
Cup volume increases gradually across the UK sizing system. A 34K has more cup volume than a 34JJ, while a 34J has slightly less.
How cup sizes actually work: Bra cup sizes are based on a simple fitting rule — each step in the cup sequence represents a 1 inch difference between the bust and underbust measurement. This rule applies across all UK brands, regardless of whether they use a traditional or extended cup letter sequence.
In brands that use an extended UK cup sequence, JJ is a separate cup size positioned between J and K. Each step represents the same one-inch increase in measurement difference, making JJ one cup size larger than J and one cup size smaller than K.
The difference between brands is the lettering used, not the size step itself. For example, some traditional UK cup sequences move directly from J to K, while extended UK sizing includes JJ as an additional cup size between them.
UK vs US Bra Sizes
Bra sizing systems vary slightly between regions. Most specialist fuller-bust brands such as Panache, Freya, Fantasie and Elomi follow the UK cup size sequence, which includes double letters such as FF, GG and HH.
Some US brands use a slightly different lettering system, which can create confusion when comparing sizes internationally. To understand how the sizing systems relate, see our UK vs US bra size comparison guide .
Is a UK JJ Cup the Same as a US JJ Bra Size?
It depends on the brand. Many UK-based fuller-bust brands such as Panache, Freya and Elomi use the same extended UK cup sequence internationally, meaning an JJ cup is labelled the same in both the UK and US.
However, some US lingerie brands follow a different cup progression. For this reason, always check the brand’s stated sizing system rather than relying on the cup letter alone.
A cup size is not one fixed volume. Cup volume increases as the band size increases, so a 32JJ, 38JJ and 44JJ are all very different in fit and capacity.
Always consider both band size and cup size together when comparing bras.
UK Brands That Make JJ Cup Bras
- Bravissimo – Bands 28–40, cups D–L View size guide
- Panache – Bands 28–40, cups D–K View size guide
- Elomi – Bands 32–46, cups D–K View size guide
- Sculptresse – Bands 34–46, cups D–K View size guide
JJ Cup Band Sizes by Brand
- Bravissimo: 28JJ, 30JJ, 32JJ, 34JJ, 36JJ, 38JJ, 40JJ
- Panache: 28JJ, 30JJ, 32JJ, 34JJ, 36JJ, 38JJ
- Elomi: 32JJ, 34JJ, 36JJ, 38JJ, 40JJ, 42JJ, 44JJ
- Sculptresse: 34JJ, 36JJ, 38JJ, 40JJ, 42JJ
JJ Cup Volume Changes With Band Size
Many people assume that all JJ cups are the same size. In reality, cup volume increases as band size increases. A 38JJ holds more volume than a 34JJ, while a 30JJ holds less.
The cup letter stays the same, but overall cup volume increases as the band size increases.
30JJ
34JJ
38JJ
These simplified educational diagrams show how cup volume changes as the band size increases, even when the cup letter remains JJ.
A bra size consists of both the band size and cup size. A 38JJ holds more cup volume than a 34JJ, while a 30JJ holds less, despite all three using the same cup letter.
Popular JJ Cup Bras (UK Sizing)
Below are selected JJ cup bras in UK sizing from fuller-bust specialist brands. These examples show styles commonly available in JJ cup sizes across a range of band sizes. If you are still confirming your size, see the fitting advice and sizing information further down this guide before purchasing.
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How to Find Your Correct JJ Cup Size
Measure your underband and bust carefully, then enter your measurements into our Bra Size Calculator to get a recommended UK starting size.
For measuring tips and fit checks, see our Bra Fitting Advice.
Common Fit Issues for JJ Cup Bras
- Band riding up at the back (often means the band is too big)
- Cups gaping or wrinkling due to shape mismatch
- Spillage at the neckline or centre of the cups
- Underwires sitting on breast tissue rather than around it
- Straps digging into the shoulders or slipping during wear
If your JJ cup fit feels inconsistent, try another style within the same brand or compare sizes using our Bra Size Converter.
Can I Sister Size Instead of Wearing a JJ Cup?
Sister sizing can be useful if your usual JJ cup size is unavailable in a particular bra. In general, moving up a band size requires moving down one cup size to maintain a similar cup volume, while moving down a band size requires moving up one cup size. Although sister sizes can offer a comparable volume, band tension and overall fit may feel different.
JJ Cup Sister Size Example
When sister sizing, the band size changes while the cup volume stays similar. A common JJ cup example is:
These sizes have a similar cup volume, but different band lengths.
Sister Size Comparison
These diagrams provide a simplified visual example of sister sizing. While the band size changes, the overall cup volume remains broadly similar.
Sister sizes can help when your usual size is unavailable. As the band size increases, the cup letter decreases to maintain a similar cup volume.
For a full explanation of how sister sizing works, see our Bra Sister Sizes Guide .
Use our Bra Size Converter to compare UK brand sizing and sister sizes accurately.
Explore More JJ Cup Guides
If you want to compare JJ cup sizes in more detail, these related guides can help you understand cup volume, band size, sister sizing and neighbouring cup sizes.
JJ Cup Bra FAQs
Is JJ cup bigger than J?
Yes. In extended UK sizing, JJ is one full cup step larger than J and one step smaller than K.
Do all brands offer JJ cups?
No. JJ cups are only available from specialist fuller-bust brands that use an extended UK cup sequence.
Most high-street brands do not produce JJ cups.
Does band size affect JJ cup volume?
Yes. A 38JJ holds significantly more volume than a 32JJ.
Always consider both band size and cup size together when assessing fit.
Can I sister size at JJ cup?
Sister sizing is rarely ideal at this cup level.
Changing band size can significantly alter support, wire placement, and cup depth.
If you are frequently sister sizing, the brand or cup shape may not be suitable.
JJ cup sits between J and K in extended UK sizing. If you're deciding between sizes, it can help to compare J cup bras and K cup bras to understand how cup volume increases across neighbouring sizes.
Related Cup Size Guides
For general background on UK bra sizing systems and cup progression, see the bra size reference on Wikipedia .