32F Sister Sizes

The sizes in bold are the ones to use. The outer two share the cup volume in theory, but are proportioned for a noticeably different frame.

When to choose 30FF

Choose 30FF if the 32 band is loose. FF is a full cup size above F, and not a half step.

When to choose 34E

Choose 34E if the 32 band is too tight and the cups fit. The cup goes down from F to E.

What a 32F measures

All three sizes are designed around a bust of about 39 inches. The difference is how much of that total is ribcage and how much is breast, which is why the band changes and the cup letter moves the other way.

Check the label system carefully at this size. A UK 32F is a US 32G. If you see 32F on an American brand, it is one cup smaller than a UK 32F.

If neither sister size works

Sister sizes only help when the cup volume is already right. If you spill out of a 32F or the cups gape, keep the 32 band and change the cup letter. If you are unsure which problem you have, when to sister size up or down will help you decide, and the calculator will give you a fresh starting size from your measurements.

Frequently asked questions

What is the sister size of a 32F?

30FF on a firmer band and 34E on a looser band. Both have the same cup volume as a 32F.

Is a 30FF the same as a 32F?

The cups hold the same volume. The 30FF has a band one size smaller, so it fits more firmly around the ribcage.

Can I wear a 36DD if I am a 32F?

That is two steps away. The cup volume is the same on paper, but the wires, straps and proportions are made for a larger frame, and the band will be four inches longer. It is unlikely to support you well.