Bra Size Converter
Find your perfect fit. Convert Band and Cup sizes between US, UK, European, and Australian standards.
Sister Sizes (Same Volume)
Fit Visualizer
Top-down view of Band vs. Cup projection.
The 'DDD' Confusion
The US system typically uses 'DDD' after 'DD'. However, the UK system uses 'E' after 'DD'. This means a US 'DDD' is exactly the same cup volume as a UK 'E'.
Sister Sizing
If a bra fits in the cup but is tight in the band, go up a band size and down a cup size (e.g., 34C -> 36B). This maintains the same cup volume.
Band Measurement
The band provides 80% of the support. A common mistake is buying a band that is too loose. The band should fit snug on the loosest hook when new.
Bra Sizing FAQs
Is a US Cup size DDD the same as a UK E?
Yes. In the US sizing system, the progression is D, DD, DDD, G. In the UK system, it is D, DD, E, F. Therefore, a US DDD is equivalent to a UK E cup.
How do 'Sister Sizes' work?
Sister sizes are bra sizes that hold the same volume of breast tissue but have different band lengths. For example, if a 34C fits your cup volume but the band is loose, the sister size 32D will keep the same cup volume with a tighter band.
Why is my European band size (e.g., 75) different from inches?
EU band sizes (65, 70, 75) refer to the underbust measurement in centimeters minus approx. 5-10cm for stretch. A US 34 band generally corresponds to an EU 75 band.
What is the difference between US and Australian bra sizes?
Australia uses a dress-size based numbering system for bands (8, 10, 12, 14). A US 32 band is an AU 10, a US 34 is an AU 12, and so on. Cup letters are generally similar to the UK system.
Complete Your Lifestyle
View HubBra Sister Sizes Explained: How to Finally Find a Bra That Fits
Band too tight? Cup too loose? The solution isn't just a new size—it's a Sister Size. We explain the math behind cup volume and how to adjust your fit.
Read Full Article