30A bra size
30A means band 30 with cup A, a difference of 1 in between bust and band, with a bust range of 30.5 to 31.5 in.
US 30A · UK 30A
- Difference1 in2.5 cm
- Underbust, underbust method29 to 31 in73.66 to 78.74 cm
- Bust for this cup30.5 to 31.5 in77.47 to 80.01 cm
Each range includes its first figure and stops just short of its last.
Which measurements give a 30A
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 | 30.5 to 31.5 in |
| Add-4 method | 24.5 to 26.5 in | 62.23 to 67.31 cm | 30.5 to 31.5 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.
30A in six sizing systems
| System | Band | Cup | Size |
|---|---|---|---|
| US | 30 | A | 30A |
| UK | 30 | A | 30A |
| EU | 65 | A | 65A |
| FR/BE | 80 | A | 80A |
| AU/NZ | 8 | A | 8A |
| JP | 65 | Not listed | Not listed |
Bands and letters are label equivalents, not body measurements. JP letters vary by brand.
Sister sizes of 30A
A sister size moves the band one step and the cup one letter the other way.
- 1 band down28B
- 1 band up32AA
For 30A, the underbust method and add-4 method do not assign band 30 to any shared underbust. Published charts disagree on the resulting band: the underbust method uses the underbust itself, while the add-4 method rounds it to the nearest whole inch before applying its rule. The EU method gives band 65 for an underbust of 62.5 cm up to but not including 67.5 cm, making this label 65A.
The 30A tag stays 30A in US and UK systems, but reads 65A in EU, 80A in FR/BE, and 8A in AU/NZ. At this difference, the cup letter is A in those systems. JP does not list a letter for the 30A cup, and one chart says to check the brand.
For 30A, the sister size with a smaller band has a larger cup letter, such as 28B in US and UK or 60C in JP. With a larger band, its sister size has a smaller cup letter, including 32AA in US and UK. The JP table does not list a sister size for this larger-band step.
Questions
What does 30A mean?
30A is a band of 30 with a cup that stands for a difference of 1 in (2.5 cm) between bust and band in US sizing.
What measurements give a 30A?
By the underbust method, an underbust of 29 to 31 in (73.66 to 78.74 cm) gives band 30, and a bust of 30.5 to 31.5 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 30A?
The sister sizes of 30A are 28B and 32AA. Each step up in band takes the cup one letter down, and each step down takes it one letter up.