G vs GG vs H Cup Size – What’s the Difference in UK Bra Sizes?
In the UK bra sizing system, cup sizes increase in a structured sequence where each step represents roughly a 1 inch increase between the bra band size and the fullest bust measurement.
The sequence around these sizes is: FF → G → GG → H → HH.
This means a GG cup is one size larger than G, and an H cup is one size larger than GG.
Many women search for the difference between G vs GG vs H cup size when trying to understand how the UK bra sizing system works. Because the UK system includes double-letter sizes such as GG and HH, it can sometimes be confusing to see where these sizes fit within the progression.
This guide explains the difference between G, GG and H cup sizes, how they relate to bra measurements, and how cup volume changes across different band sizes.
G vs GG vs H Cup Size Comparison
The table below summarises how G, GG and H cup sizes compare within the UK bra sizing system. Each step represents roughly a one-inch increase in the difference between the band size and the bust measurement.
| Cup Size | Relative Size | Bust Difference |
|---|---|---|
| G | Smaller than GG and H | 9 inches |
| GG | Larger than G but smaller than H | 10 inches |
| H | Larger than G and GG | 11 inches |
G vs GG vs H Cup Size – Where These Sizes Fit in the UK Cup Sequence
The UK bra sizing system includes several double-letter cup sizes such as DD, FF, GG and HH to create a more gradual progression between cup volumes.
FF → G → GG → H → HH
Each step represents roughly a 1 inch increase in the difference between the bra band size and the fullest bust measurement.
These additional steps help brands offer a wider range of fits, particularly for fuller-bust sizes. If you want to understand how these sizes work in more detail, see our Double Cup Bra Sizes Guide.
You can also explore the full progression in our UK Bra Cup Size Chart.
If you are adjusting band sizes when trying different bras, you may also need to use bra sister sizes. Sister sizing keeps a similar cup volume while changing the band measurement.
G vs GG vs H Cup Size Measurement Difference
The difference between G, GG and H cups is based on the increase in the measurement difference between the band size and the bust measurement.
| Cup Size | Difference Between Band Size and Bust |
|---|---|
| G | 9 inches |
| GG | 10 inches |
| H | 11 inches |
Cup size is not a fixed volume.
For example, a 32G, 36G and 40G all have different cup capacities because cup volume increases as the band size increases.
Example Bust Measurements by Band Size
Because cup size works together with band size, the same cup letter represents different bust measurements depending on the band.
| Band Size | G Cup | GG Cup | H Cup |
|---|---|---|---|
| 32 | 41" | 42" | 43" |
| 34 | 43" | 44" | 45" |
| 36 | 45" | 46" | 47" |
| 38 | 47" | 48" | 49" |
Why Double Cup Sizes Exist
The UK bra sizing system includes double cup sizes such as DD, FF, GG and HH to provide additional steps between single-letter cup sizes.
These extra steps allow brands to offer a wider range of fits, especially in fuller-bust sizes.
For a full explanation, see our Double Cup Bra Sizes Guide.
Explore Individual Cup Guides
Cup Size Comparison Questions
Yes. In the UK bra sizing system, GG comes directly after G. The sequence progresses G → GG → H, meaning each step represents roughly a one-inch increase in bust measurement relative to the band size.
Yes. The sequence continues G → GG → H, so H is one cup size larger than GG.
The next cup size after H in the UK system is HH.
G vs GG vs H Cup Size and Other Cup Size Comparisons
If you are comparing neighbouring cup sizes, understanding the difference between G vs GG vs H cup size can help clarify how the UK bra sizing system progresses.
- G vs GG cup size: GG comes directly after G in the UK cup size sequence. See our guide to GG cup bras.
- GG vs H cup size: H is one cup size larger than GG in the UK progression. You can explore typical styles in our H cup bras guide.
- H vs HH cup size: HH is the next cup size after H and represents another step in the extended UK sizing system. See examples in our HH cup bras guide.
- HH vs J cup size: J comes directly after HH in the UK cup progression.
Each step represents roughly a 1 inch increase in the difference between the bra band size and the fullest bust measurement.
Understanding how sizes progress from G → GG → H can make it easier to compare neighbouring cup sizes and choose a comfortable bra size within the UK sizing system.
Explore Each Cup Size by Band Size
While comparing G, GG and H cups helps explain how sizes progress, the best fit also depends on your band size. You can explore how each cup size behaves across different band measurements in our detailed guides:
These guides break down how cup volume changes with band size and link to the best bras for each individual size.
These guides break down how cup volume changes with band size and link to the best bras for each individual size.
Find Your Correct Bra Size
If you are unsure which bra size to start with, measure your bust and band using our Bra Size Calculator.
You can then confirm your fit using our Bra Fitting Advice and compare international sizing systems using our Bra Size Converter.
For additional background on how bra sizing systems developed, you may also find this bra size overview useful.