Bra Sizing Guide

There are three important steps to finding the correct bra for you. Back size, cup size, and finally the style of bra you want. The advice below suggests a way for you to tell if you are already wearing the correct size, or if you need to alter the size. There is also a link at the bottom of the page to calculate your size based on measurements using a tape measure. You can also go into most underwear shops or department stores for a fitting and advice on choosing the correct bra.

1. Back size.

This refers to the number used in UK sizes. E.g. the '36' in a 36B size. If the back of your bra is too big you won't get the cup right.

A correctly fitted bra should fit firmly around your back. It should not be so tight that it is uncomfortable, but it is important that it is tight enough in order to offer full support. A good-fitting bra's main support comes from the back band, not the straps (which is why a well-fitting strapless bra still keeps you up!). A loose band will therefore not only reduce the bra's supportiveness, but also mean that more of the weight has to be taken by the shoulder straps, causing them to dig in.

If the back of your bra tends to ride up, it is probably because the back is too big for you. The back should stay parallel with the front of the bra.

A test you can do is to put your hand flat between your back and the back of your bra, then try to turn your hand at 90 degrees to your back. If you have the correct back size, your hand should be quite firmly wedged and you should not be able to pull the bra much further than a few centimetres away from your back. If it can be pulled further, you need to go down at least one back size. A new bra should pass this test with the clasp on the loosest fitting - this allows you to tighten the bra as it can stretch up to 4 inches with wear and washing. Never fit yourself into a new bra with the clasp on its tightest fitting.

2. Cup size

Once you are happy with your back size you can then address the cup size.

If you need to change to a smaller back size (which a fair few women do), you may also need to opt for a larger cup, because often one compensates for the other.

Did you know? A 'C' cup on a 34 back bra is bigger than a 'C' cup on a 32 back bra. The wire on an underwired style gets larger as the back size increases, even when the cup letter stays the same!

You will probably need to increase the cup letter for every decrease in back size, if you want to keep the cup the same size, and vice versa. For example, if you have been wearing a 36B bra, and you have just discovered by trying the back test explained above, that you should really be in a 34 back bra, you will now need a C in a 34 (assuming you do not need to adjust the cup size too).

It is straight forward to spot if your cup size is too big. Basically you won't be filling the cups properly, and will need to drop a cup. It is more likely that if the cups aren't fitting you properly it is because they are too small. The signs to look for are breasts bulging over the top and sides of each cup, and the wires of an underwired bra not sitting back against the chest wall of the cleavage. If the band of your bra is tight enough, it will be attempting to pull the underwires up against your body. If the size is correct, the cups will go around each breast and sit snugly against your rib cage, with each breast in it's cup. If not, you will need to increase the cup size.

3. Bra style

A full cup bra with shoulder straps placed centrally to each cup will suit most people, and provides full coverage. A minimiser full cup bra will help to flatten a larger bust. A half-cup or balconette bra with widely spaced shoulder straps will provide uplift. Push-up and plunge styles both uplift and give maximum cleavage. Also see section on different types of bras.

For More Information see:

The Figleaves measuring guide or Contessa has more advice and trouble shooting help.