Bra Size Converter
Find your perfect fit. Convert Band and Cup sizes between US, UK, European, and Australian standards.
Sister Sizes (Same Volume)
Visualizer
Cup C Projection
Add this calculator to your website
Want to use this tool on your blog or website? Copy the code below.
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