Bra Size for Fuller Busts and Larger Bands
For fuller busts and larger bands, measure the same way: snug underbust for the band and the bust at its fullest, ideally leaning forward and lying down too. Cup letters go well past DD; UK sizes continue E, F, FF, G, GG, H. Specialist brands carry wider ranges, so check their own charts.
Enter your measurements
The calculator needs JavaScript. Without it, use the steps and the size chart below: measure your snug underbust and your bust in inches, round the underbust to the nearest even number for the band, and count one cup letter per inch of difference.
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Your starting size
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Sizes vary between brands and styles. Use this as a starting point and try bras on: the band should sit level and feel firm on the loosest hook.
Next: sister sizes explained · convert to other countries · measuring tips
Cup letters past DD
| Bust − band | In cm (approx.) | US cup | UK and AU cup | EU and French cup |
|---|---|---|---|---|
| under 1" | under 2.5 cm | AA | AA | AA |
| 1" | 2.5 cm | A | A | A |
| 2" | 5.1 cm | B | B | B |
| 3" | 7.6 cm | C | C | C |
| 4" | 10.2 cm | D | D | D |
| 5" | 12.7 cm | DD/E | DD | E |
| 6" | 15.2 cm | DDD/F | E | F |
| 7" | 17.8 cm | G | F | G |
| 8" | 20.3 cm | H | FF | H |
| 9" | 22.9 cm | I | G | I |
| 10" | 25.4 cm | J | GG | J |
| 11" | 27.9 cm | K | H | K |
| 12" | 30.5 cm | – | HH | L |
| 13" | 33.0 cm | – | J | M |
| 14" | 35.6 cm | – | JJ | N |
| 15" | 38.1 cm | – | K | O |
One cup letter per inch of difference. The EU letters show the label conversion of the same UK cup.
Measuring tips for fuller busts
- Use all three bust measurements. Leaning forward and lying down often catch what a standing measurement misses.
- Keep the band tape level. It easily slides up at the back; a mirror or a helper makes it easier.
- Do not compress. The bust tape rests on the body without pulling in.
Band and fit
A firm band does most of the supporting. If the cups fit but the band feels too tight, the sister size up keeps the cup volume. Sizes are not standardised between brands, countries or even styles from the same brand. A calculator gives you a good place to start; how the bra actually feels on your body decides.
Frequently asked questions
What bra size is considered plus size?
There is no fixed definition. Retailers use the term for larger bands, larger cups or both. The measuring method is the same for every size.
What comes after DD?
In UK sizes the cups go DD, E, F, FF, G, GG, H, HH, J, JJ, K. In US sizes they usually go DD/E, DDD/F, G, H, I, J. Convert carefully if you compare brands from different countries.
Why do I need to measure leaning forward?
With a full or soft bust, standing can miss tissue that falls forward. Leaning forward and lying down give a fuller picture. The calculator averages the measurements you enter.
Is a bigger band more comfortable?
Not always. A band that is too loose shifts weight onto the straps, which many people feel in their shoulders. Look for a firm band; try a sister size up only if it feels too tight.
What if the calculator shows a cup beyond K?
Some specialist brands make cups beyond K, each with their own charts. Use your measurements in centimetres or inches with the brand’s chart, since their letters may not follow the same steps as this site.
Do I need a wider band?
Some people with larger bands prefer wider bands with more hooks for comfort. It is a matter of preference, so try a few styles and choose what feels best.
Last updated: October 15, 2026