Bra Fitting Guide

Finding a bra that fits you perfectly is essential for comfort and support.  Not only that, it instantly improves your posture, gives you a better shape and can improve the fit of your clothes.  Wearing the correct size bra can even eliminate aches and pains experienced from badly supported breasts, and reduce your chances of sagging.  


Bra Components


It is estimated that as many as 80% of women are wearing the wrong size bra, so make sure you’re not one of them with our simple bra fitting guide.


Putting Your Bra On

Although this may seem obvious, it is important to put your bra on correctly.  The first time you put on a bra you should have the straps at full length.  Hook your arms through, gently lean forward into the cups and fasten the bra at the back. Using your hand ensure that the breasts are complete enclosed in the cups.  Then slide the straps off your shoulders, and shorten them until they are comfortable.  Remember, the back should provide most of the support so the straps should not dig in.


Always fit your bra to the loosest hook and eye; when it inevitably loses elasticity over time, you can tighten it, thus prolonging the life of the bra.  If the first time you try a bra it is fits on the tightest setting then go down a back size.  As a general rule, if you go down a back size you should increase the cup size, so if you were wearing a 34DD, and the back is too loose, then you should try a 32E.  The table below illustrates equivalent sizes.


28 30 32 34 36 38 40 42 44
 28A  30AA              
 28B  30A  32AA            
 28C  30B  32A  34AA          
 28D  30C  32B  34A  36AA        
 28DD  30D  32C  34B  36A 38AA
 28E  30DD  32D  34C  36B  38A  40AA    
 28F  30E  32DD  34D  36C  38B  40A 42AA
 28FF  30F  32E  34DD  36D  38C  40B  42A 44AA
 28G  30FF  32F  34E  36DD  38D  40C  42B  44A
 28GG  30G  32FF  34F  36E  38DD  40D  42C 42B
 28H  30GG  32G  34FF  36F  38E  40DD  42D  42C
 28HH  30H  32GG  34G  36FF  38F  40E  42DD  44D
 28J  30HH  32H  34GG  36G  38FF  40F  42E  44DD
 28JJ  30J  32HH  34H  36GG  38G  40FF  42F  44E
 28K  30JJ 32J
 38GG  40G  42FF  44F
   30K  32JJ  34G 36HH
 38H 40GG
 42G 44FF

Finding the Right Band Size

The band size relates to the how the bra fits around your body.  One of the most common mistakes is wearing a back size that is too loose, which can cause the bra to ride up at the back; this means that the breasts are not properly supported.  The back of the bra should be horizontal and level all the way round; if you find that this is not the case, try a smaller back size, and thus a larger cup size.

Finding the Right Cup Size

The cup size relates to the fullness of your bust.  The centre front and underwire should sit flat against the breastbone between your boobs.  Your breasts should be completely enclosed by the fabric of the cup, and there should be a smooth line with no overspill at the top of the bra.  If you find your boobs are bulging over the top of the cup or that the fullness of your bust is pushing the wires away from your body, then try a larger cup size.  If you have excess fabric or wrinkling in the cups then try a smaller size bra.  If you increase the cup size you should also decrease the back size.

Professional Fitting

We hope that our simple bra fitting guide has helped you out, but we emphasise that this is not a substitute for being professionally fitted.  If you’ve not has a bra fitted for a while, or ever for that matter, it’s definitely worth doing.  Experts recommend being fitted every six months as there are numerous factors that can influence your bra size, such as; weight changes, your monthly cycle, pregnancy and hormone changes from HRT or taking the pill.

Also, it is worthwhile remembering that different styles of bra (see our bra style guide) fit differently on varying body shapes, so you may not require the same size in a full cup bra as you do in a balcony.  There is considerable variation between manufacturers too, so that’s why we offer free delivery and free UK returns so you can try as many as you like until you get the fit that is right for you.

Common Bra Sizing Problems


Always remember the general rule that if you decrease the band size, you need to increase the cup size in proportion, and the same vice versa.  (Please see our table of equivalent sizes).


Bra Band

The band rides up at the back

If this is the case, then your breasts are not properly supported, as the majority of support comes from the under band.  A good way to test if the under band it too loose is to loosen the straps; the band should still hold you in place even if you lift your arms or move around.  If it doesn’t then you should try a smaller back size.

Bra Straps

Shoulder straps dig in

This is frequently caused by the band size being too large and consequently the straps are taking the strain.  If when the straps are loosened the band does not provide enough support then try a smaller back size.



The bras centre front is lifted

The centre front should lie flat against the body, if it does not then try a larger cup size.


The underwire digs in

If the underwire pinches or digs in under the arm; the cup size is probably too small.  You should ensure that the entire breast is enclosed in the underwire.

Cup Fitting

Breasts spill over the bra cups

If you breasts spill over the top of the cups, then the cup size is too small.  When you try on a bra, put a t-shirt over the top, so that you can see if you have a smooth line through clothing.


Bra cups are baggy

If you have excess fabric, and the cups are wrinkled then the cups may be too big.  Although, if the cups fit well, but crease where they meet the strap it may be that the bra is too high for your shape.  In this case something which finishes lower down such as a balcony bra may suit your shape better.  For more information on this see our bra style guide.