30DD bra size
30DD means band 30 with cup DD, a difference of 5 in between your bust and the band; the label identifies the cup by that gap.
US 30DD, also written 30E · UK 30DD
- Difference5 in12.7 cm
- Underbust, underbust method29 to 31 in73.66 to 78.74 cm
- Bust for this cup34.5 to 35.5 in87.63 to 90.17 cm
Each range includes its first figure and stops just short of its last.
Which measurements give a 30DD
The label is a band and a cup, not a body measurement. Each of the three published rules turns the same label into different measurements.
| Method | Underbust (in) | Underbust (cm) | Bust (in) |
|---|---|---|---|
| Underbust method | 29 to 31 in | 73.66 to 78.74 cm | 34.5 to 35.5 in |
| Add-4 method | 24.5 to 26.5 in | 62.23 to 67.31 cm | 34.5 to 35.5 in |
| EU method, band 65 | 24.61 to 26.57 in | 62.5 to 67.5 cm | Cup read in cm |
Each range includes its first figure and stops just short of its last.
30DD in six sizing systems
| System | Band | Cup | Size |
|---|---|---|---|
| US | 30 | DD/E | 30DD/E |
| UK | 30 | DD | 30DD |
| EU | 65 | E | 65E |
| FR/BE | 80 | E | 80E |
| AU/NZ | 8 | DD | 8DD |
| JP | 65 | F | 65F |
Bands and letters are label equivalents, not body measurements. JP letters vary by brand.
Sister sizes of 30DD
A sister size moves the band one step and the cup one letter the other way.
- 1 band down28DDD
- 1 band up32D
- 2 bands up34C
For 30DD, the underbust method and add-4 method give band 30 from separate underbust ranges. The underbust method uses 29 in up to but not including 31 in, while the add-4 method uses 24.5 in up to but not including 26.5 in. The EU method pairs this size with band 65, using 62.5 cm up to but not including 67.5 cm. The methods disagree: no underbust falls in both band 30 ranges.
A bust of 34.5 to 35.5 in maps to cup DD on band 30 under both methods. The US label is 30DD/E, while the UK label is 30DD; EU sizing writes the label as 65E. The same cup difference appears as 8DD in AU/NZ, 80E in FR/BE, and 65F in JP.
The JP cup letter for 30DD is F, while the EU letter is E, and JP letters vary by brand. For this size, the sister size one band step down is 28E in UK sizing; the sister size one step up is 32D. One published chart reports additional US labels D1 to D5, E, EE and EEE for the difference, while other published charts do not.
Questions
What does 30DD mean?
30DD is a band of 30 with a cup that stands for a difference of 5 in (12.7 cm) between bust and band in US sizing.
What measurements give a 30DD?
By the underbust method, an underbust of 29 to 31 in (73.66 to 78.74 cm) gives band 30, and a bust of 34.5 to 35.5 in gives this cup. By the add-4 method, band 30 comes from an underbust of 24.5 to 26.5 in. Each range includes its first figure and stops just short of its last.
What are the sister sizes of 30DD?
The sister sizes of 30DD are 28DDD, 32D and 34C. Each step up in band takes the cup one letter down, and each step down takes it one letter up.