The way a bra is cut, assembled and sewn has a big impact on how it fits your unique shape. In this section we'll dissect each part that goes into a bra and explain its function and how it affects your bra fit.
A bra with underwires gives the best shape and definition to a bustline. So, itās worth the effort to try and find an underwire bra that fits you properly. Understanding underwires and how they are sized can go a long way in helping you find the right underwire bra fit.
Breasts have a diameter measurement and a projection measurement ā meaning the distance the breast tissue protrudes from the chest wall. When you select a cup size such as a C or G, you are making a breast projection measurement selection. The breast diameter measurement is pre-determined by the manufacturer and built into each band size. So, changing your band size also changes your underwire diameter. Here is an example: Going from a 34C to a 36C takes you up one breast diameter measurement. Going from a 34C to a 36B keeps the same breast diameter measurement. This is why going up a band size means you also need to go down a cup size if you want to keep the same cup volume. Confused? Youāre not alone.
Manufacturers use the exact same underwire size in multiple band sizes. For example, the actual underwire used in a 36B is the exact same underwire used in a 34C, 32 D1 and 30 D2. All these bras have the same breast diameter and cup volume, but different breast projection measurements in relation to the band size.
The chart below makes this a little clearer. Find your size on the chart and note the color in the box. All the other sizes in the same diagonal color stripe use the exact same underwire size. Note that Universal Cup Sizingā¢ is used after A through C cups. If youāre not sure what your Universal Cup Sizeā¢ is, refer to the information below the chart.
30A
30B
30C
30 D1
30 D2
30 D3
30 D4
30 D5
30 D6
32A
32B
32C
32 D1
32 D2
32 D3
32 D4
32 D5
32 D6
34A
34B
34C
34 D1
34 D2
34 D3
34 D4
34 D5
34 D6
36A
36B
36C
36 D1
36 D2
36 D3
36 D4
36 D5
36 D6
38A
38B
38C
38 D1
38 D2
38 D3
38 D4
38 D5
38 D6
40A
40B
40C
40 D1
40 D2
40 D3
40 D4
40 D5
40 D6
42A
42B
42C
42 D1
42 D2
42 D3
42 D4
42 D5
42 D6
44A
44B
44C
44 D1
44 D2
44 D3
44 D4
44 D5
44 D6
Universal Cup Sizingā¢ Cup sizes larger than a D are called different letters by different brands (a DDD cup size in one brand can be called an E or F in other brands). So know your Universal Cup Sizeā¢ and you can find your correct size in any brand at HerRoom. Learn how to find your Universal Cup Sizeā¢.
So, hereās how you can use this newfound knowledge. Say you find a bra that fits perfectly in the cups but the band is too tight. As you look at the above chart, if you follow it diagonally downward, youāll find your A through C or UCSĀ® with just a larger band size. The cup size went down one size as your band size went up one size. But both cups use the same underwire, so you know your cups will be the same. Conversely, if want a smaller band size but with the same cup volume, follow your size diagonally upward on the chart to get the same cup size but a smaller band size.
This chart also explains why an underwire swimsuit that is labeled as a C cup will not fit all C cup women ā you really need to know what underwire size was selected to represent C cups. For the analytical types, the standard diameter deviation between underwire sizes is about 3/8". The standard underwire length deviation between sizes is about 5/8".
Underwire design is also important. An underwire is designed to have some spring. Usually made of heavy gauge wire, sheet metal or a plastic, underwires are designed to splay or spread wider once a bra is put on and fastened. Itās kind of like stretching a spring. Once a bra is removed from your body, the underwires return to their original shape. This horizontal pulling on the underwires gives additional support and containment to your breasts ā especially for strapless bras.
Do you have a problem with your underwires breaking in their middle? If so, itās because too much horizontal pulling is taking place with your underwires. Your breasts are in too small of an underwire and their weight and pressure is causing eventual breakage. Your band size could also be too small and the excessive pulling apart of the underwires is causing their eventual breakage.
Are all underwires shaped the same? For the most part, yes. But there can be some differences. Many lingerie manufacturers claim their underwire grading and shaping is their secret behind their unique fit. So, this could be a reason why you find one bra brand fitting you differently than another.
There are many different underwire lengths, as well.Demi cup, low-plunge bras and petite bra styles have shorter wires due to their design. Thus, these specific bra styles can be a great choice for a petite or short-waisted woman who has issues with underwires coming up too high in the center or under the arms. The longest underwires are used in strapless bras. Since a strapless bra does not have the benefit of straps for support, having more underwire surrounding and containing the breasts helps give the needed support to keep a strapless bra up and in place.