Sister Sizing: A Measurement Analysis of PrimaDonna Deauville

Following up on our initial Sister Sizing article, we've taken a number of key measurements from an assortment of PrimaDonna Deauville bras. These measurements will show you just how similar, or the same, bras in sister sizes can be.

Using the following template for comparison, we've measured:

1. Band Length
2. Stretched Band
3. Cup Width (from end point of wires across)
4. Cup Depth
5. Wire Length
6. Cup Separation
7. Centre Gore Height
8. Wing Height
9. Strap Width
10. Number of Hooks per Column

PrimaDonna Deauville measurements - F cups

In the measurement chart below for the F cups, from 70 to 90, you can see how the the cup width, cup depth and wire length change in each band size showing that not all F cups are equal. The width of the cup increases by approximately 7mm per size and the cup depth by approximately 14mm. The wires grow by nearly 14mm in length per size, and the gore and wing heights increase by a few millimetres with each size larger.



Cup width of 15.7cm on the 80F
Cup width of 16.3cm on the 85F

PrimaDonna Deauville measurements: 70I - 75H - 85G - 85F - 90E cups

In the second measurement chart, the sister sizes 70I, 75H, 80G, 85F and 90E, you can see how the cup width, cup depth and wire length measurements are similar to each other. The measurements differ only by a few millimetres, due to measuring inaccuracies. The cup width is fairly constant with measures falling between 16.1cm and 16.5cm. The cup depth varies slightly more, and I can assure you that's because it was very difficult to measure with only two hands. The measurements also show that the centre gore and wing height are all also incredibly similar - so it's more than just the cups, it also includes the proportions of the cradle of the bra. The 'same' cup size is fitting into a very similar cradle.


Cup width of 16.3cm on the 85F (same as above)
Cup width of 16.2cm on the 70I

The only size that was noticeably different was the 90E, which can be explained as a different style. All of the bras, except for the 90E, are the PrimaDonna Deauville 016-1811, and the 90E is style 016-1810. The most noticeable difference is that the wire is slightly shorter, indicating that the bra has a slight difference in height under the arm with less coverage.

Finally, you can see that there are also some 'standards' to the bras. In the larger band and cup sizes the width of the straps change from 2.2cm to 2.5cm, and with the 2.5cm straps, the bra will also have three rows of hooks on the back closure. A lot of care and concern has gone into the development of all of these sizes when you realise as well that the smallest bra size has an even thinner shoulder strap. Over the styles in the collection, at least three widths of strap elastic are utilised, as well as three different sizes of hook and eye closures.

Three different F cups with different hook and eye widths.
Three different F cups with different strap widths.


By understanding sister sizing, shopping for new brands and styles can be easier as every brand, and style fits differently. Knowing when and how to adjust the size you need will make sure that you select a bra that is comfortable, fits well and gives you the support and shape that you're looking for.


We hope you find this information helpful in knowing more about how to purchase a bra, and as always, if you have any questions, please contact us for advice.