G Cup Comparison Tool: Band and Cup Sizes
Compare two complete sizes and see band differences, aligned cup positions and nominal sister-size relationships.
Keep both systems visible. A 34G UK and 34I US align on the same chart; a 34G UK and 36FF UK are adjacent sister sizes.
Compare two complete sizes
Starts with a labelled example. Change the inputs below to calculate your own comparison.
Visual comparison of your two complete sizes
Changes with the inputs above. This is a garment and label diagram, not a body prediction.
Freya international size chart · Method and limitations. Size labels do not guarantee fit or stock availability.
| Compare G with | UK same-band step count | US same-band step count |
|---|---|---|
| C | 6 steps | 4 steps |
| D | 5 steps | 3 steps |
| DD | 4 steps | 2 steps |
| DDD | Not in this declared sequence | 1 steps |
| E | 3 steps | Not in this declared sequence |
| F | 2 steps | Not in this declared sequence |
| GG | 1 steps | Not in this declared sequence |
| H | 2 steps | 1 steps |
| J | 4 steps | 3 steps |
Three different comparisons
Schematic comparison, not a body-shape prediction. Read the method.
The tool separates the band-label difference, cup position on the aligned UK/US ladder, and nominal cup-capacity change after accounting for the band. These answer different questions and should not be treated as one number.
Worked example: 34G UK and 36G UK
Schematic comparison, not a body-shape prediction. Read the method.
Both labels have the same cup position, but the second band is one step larger. The second bra therefore has greater nominal cup capacity. A 36FF UK is the closer adjacent capacity match to 34G UK.
What the result cannot tell you
Schematic comparison, not a body-shape prediction. Read the method.
Nominal grading does not measure tissue volume, breast weight, projection or comfort. It cannot replace trying a bra or identify a single best shape from a pair of labels.
Read each output as a separate question
Schematic comparison, not a body-shape prediction. Read the method.
A band difference answers how the labelled frame changes. An aligned cup-position difference answers where the letters sit in a shared ladder. A nominal capacity comparison then considers both the band and cup step. Two labels can have different letters but similar nominal capacity, or identical letters but different capacities.
For example, 34G UK to 36FF UK combines one band step up with one cup step down. By contrast, 34G UK to 36G UK increases the band without reducing the cup step. The latter is not a sister-size move even though the letter remains G.
Choose a comparison that isolates the problem
Schematic comparison, not a body-shape prediction. Read the method.
To investigate cup capacity, hold the band and style constant where possible. To investigate band tension when the cups already fit, compare an adjacent sister size. To investigate shape, compare constructions while keeping a reasonable starting size. Changing brand, band, cup and construction at once makes the result harder to interpret.
Interpret the three comparisons separately
Schematic comparison, not a body-shape prediction. Read the method.
The band result describes the labelled frame. The cup-position result aligns UK and US sequences before comparing their positions. The capacity result then adjusts for the band change using the nominal sister-size relationship. Keeping these outputs separate prevents a higher letter from being mistaken for a larger cup in every possible pair.
UK 34G and US 34I have the same band and aligned cup position in this chart, so their nominal capacity change is zero. UK 34G and UK 36FF also show zero nominal capacity change, but the second band is larger. Those are different relationships: regional label alignment in the first case and adjacent sister sizing in the second.
What happens when the comparison changes two variables?
Schematic comparison, not a body-shape prediction. Read the method.
With UK 34G and UK 36G, retaining G while increasing the band produces one greater nominal capacity step for the second size. With UK 34G and UK 34GG, the band stays fixed while the cup position increases one step. Both calculations produce a one-step difference, but the frame changes only in the first example.
Do not turn that step count into a percentage, weight or millilitre amount. It expresses relative grading within the model, not a measured physical volume. Use the comparison to decide which variable to hold constant during a try-on, then inspect the actual garment.
Compare G with C, D, DD, DDD, E, F, GG, H or J
Schematic comparison, not a body-shape prediction. Read the method.
Use the two complete-size selectors above for any listed pair. Keep both bands equal to isolate the cup-sequence difference; change a band only when your question involves different complete sizes. The table counts transitions between cup labels, not the number of letters printed.
DDD is available in this site’s US sequence, while E, F and GG are UK labels here. Manufacturer aliases must be checked separately. For example, UK F and US G align on the named chart, although UK F and UK G are different positions. A chart comparison does not establish body volume or identical fit.
Common questions
Where should I start with g cup size comparison?
Does the guide guarantee a perfect fit?
Sources & method
The source names below identify the chart and fitting references used. Worked examples use our documented independent method; they are not product tests or fit guarantees.
- Freya international label chart
- Bravissimo fitting guide
Found a chart mismatch or unclear explanation? Tell us which page and sizing system.