Home » Comparison » D Cup vs DD Cup Bra Sizes In Review

D Cup vs DD Cup Bra Sizes In Review

As an Amazon Associate we earn from qualifying purchases.

Which is bigger than a D cup and a DD cup? How can you identify if you are a D or a DD? D and DD cups may appear all the same but they are not. So if you are wondering how D cup vs DD cup is different, you have come to the right place.

D Cup vs DD Cup General Overview

In 1937, the concept of sizing a bra was introduced in the United States, and in 1948, it was also introduced in the United Kingdom. The bra sizing started with only A, B, C, and D. For so long, people just recognized every bigger size as D. So, how was the DD cup developed? 

Woman with a DD cup size wearing a black bra

Let’s take a look at the general overview between a D cup vs DD cup:

Win a free Michael Kors Handbag

D Cup

A D cup is the fourth largest size among the bras. In fact, it is considered as the first big size among the chart. The sizes and the letters below D are considered small. Having a D cup size bra means that your breasts are sticking out 4 inches away from your ribcage. 

Furthermore, a D cup has many variations when it comes to band sizes. The common D cup sizes are from 32D up to 44D. As a matter of fact, 36D is the most common or average cup size in the UK. In other countries, the D cup is still counted as a larger size rather than just average.

DD Cup 

In the 1950s, after the DD cup was recognized by different famous brands in the US, the UK followed through with the name E. So, if you are seeing a DD or an E cup in the sizing chart, people consider them the same. Both of them are 5 inches protruding away from your chest.

If we are talking about traditional, the four main sizes are still considered as the most used and common ones. That’s the reason why when you go to the department store, you will have a hard time looking for a DD or above. Nevertheless, the DD cup is now acknowledged as the average size in the US (Source). 

Similarities and Differences

You might think that a D cup and DD cup are all the same because of their name or because there’s only an inch difference between them. Here are some of the similarities and differences between D and DD cups to help you distinguish them:

Woman with a D cup size wearing a blue bralette
  • D and DD cups can have the same band length but different cup volumes. This slight difference can highly affect the way your bra fits and supports you. For example, you can see in the size that there are 34D and 34DD. It means that they have the same band length, perhaps because of your body shape. 
  • If you are a 34D and you wear a 34DD, you will feel the difference when it comes to the cups, which might be loose and vice versa.
  • Both of these sizes need more support especially on the under band because if you are a D or DD cup, your breasts are heavier. 
  • Unsupportive and uncomfortable bras may cause pain and discomfort especially if you’re wearing them all day. Proper lifting is also necessary to prevent sagging.

How Big Are D and DD Cups?

To help you imagine how big D cups and DD cups are, here’s a visual input. If you are a D cup, your breasts may feel like you have a regular size rabbit on your chest which can weigh from 4 to 6 pounds. A D cup usually weighs up to 2 pounds per breast.

For a DD cup, imagine having a large chicken in front of you which can be as heavy as 5 to 10 pounds. A DD cup can weigh up to 6 pounds, 3 pounds on each breast, or heavier. Although sometimes, in the UK they do not consider a DD as an E. Chances are, the breast weight may also change as well.

D Cup and DD Cup Sister Sizes

Sister sizing is done when you or the bra fitter cannot find the exact size for you. Sister sizing is a more recommended method of getting a good fit rather than going up or down a cup. The wrong size of the cup can cause too many problems. 

Woman wearing a red bra sitting on bed

For instance, a smaller cup for you cannot accommodate all of your breast tissues. Therefore, it will result in spillages, such as side fat and front spills. The wrong band length can also cause back fat and insufficient support. The bra will also slide up with your every movement causing your breasts to peek at the bottom.

If the cup is big, you may see some wrinkles on your shirt. Sometimes, when you move, the loose cups will be very obvious, too. A big size bra can also result in too much bouncing, therefore, causes the breasts to sag. So here are some of the sister sizes of D and DD cups to prevent settling to a small or big size for you:

  • If you are a 28D cup, your sister sizes are 26DD, 30C, 32B, 34A, and 36AA.
  • If you are a 28DD, your sister sizes are 30D, 32C, 34B, 36A, and 38AA.

As you may have noticed, most of the sister sizes are just an increasing even number on the band length by two inches and the cup size is either going up or down. Sister sizing can either go left or right of the chart. 

Which Cup Size Is Better?

In the end, your proper size will still matter. A D and a DD cup are both considered average sizes and you may sometimes have difficulty in finding the right bra for you. No matter what, always take your proper measurement. Do not just rely on whatever you think your size is. 

Remember, numbers don’t lie. So whether you are a D cup or a DD cup, as long as you have the right bra, that will be the best for you. Only consider sister sizing if you really have no choice and your exact size is not available.


Hi there, I’m Allena, Founder and Editor of The Better Fit. I’ve always had a passion for finding ways to help women improve various areas of their lives. I have researched and worked to create this website so women would have a place to come and be informed about an article of clothing they literally wear every day.