30D bra size
30D means band 30 with cup D, a bust-to-band difference of 4 in (10.2 cm), rounded to whole inches.
US 30D · UK 30D
- Difference4 in10.2 cm
- Underbust, underbust method29 to 31 in73.66 to 78.74 cm
- Bust for this cup33.5 to 34.5 in85.09 to 87.63 cm
Each range includes its first figure and stops just short of its last.
Which measurements give a 30D
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 | 33.5 to 34.5 in |
| Add-4 method | 24.5 to 26.5 in | 62.23 to 67.31 cm | 33.5 to 34.5 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.
30D in six sizing systems
| System | Band | Cup | Size |
|---|---|---|---|
| US | 30 | D | 30D |
| UK | 30 | D | 30D |
| EU | 65 | D | 65D |
| FR/BE | 80 | D | 80D |
| AU/NZ | 8 | D | 8D |
| JP | 65 | E | 65E |
Bands and letters are label equivalents, not body measurements. JP letters vary by brand.
Sister sizes of 30D
A sister size moves the band one step and the cup one letter the other way.
Cup D on band 30 covers a bust of 33.5 in up to but not including 34.5 in (85.1 cm up to but not including 87.6 cm). The underbust method places band 30 at an underbust of 29 in up to but not including 31 in (73.7 cm up to but not including 78.7 cm).
Published charts disagree on the underbust range for band 30: the underbust method uses the underbust itself, while the add-4 method adds 4 or 5 inches. That method gives 24.5 in up to but not including 26.5 in (62.2 cm up to but not including 67.3 cm). The EU method gives band 65 at 62.5 cm up to but not including 67.5 cm (24.6 in up to but not including 26.6 in). Labels are 30D in US and UK, 65D in EU, 80D in FR/BE, 8D in AU/NZ, and 65E in JP. Cup letters match in the first five systems; JP uses E, and its letters vary by brand.
The listed sister sizes include 28DD/E in US, 28DD in UK, 60E in EU, 75E in FR/BE, 6DD in AU/NZ, and 60F in JP; others include 32C and 34B in US and UK. A sister size changes the band fit. People measure again and try on.
Questions
What does 30D mean?
30D is a band of 30 with a cup that stands for a difference of 4 in (10.2 cm) between bust and band in US sizing.
What measurements give a 30D?
By the underbust method, an underbust of 29 to 31 in (73.66 to 78.74 cm) gives band 30, and a bust of 33.5 to 34.5 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 30D?
The sister sizes of 30D are 28DD, 32C and 34B. Each step up in band takes the cup one letter down, and each step down takes it one letter up.