Does weight affect bra size?

Megan Smith
 min read

Does weight affect bra size? Or is this a persistent myth?

does weight affect bra sizeWe’ve all experienced our breasts changing size due to weight loss or gain!

The extent, however, of that impact is determined according to the individual.

Each of us is different, but some things are common to all…

Does weight affect bra size? Introduction

You might be interested to learn how weight fluctuations can affect your breast size and shape.

Bummed out about it? No worries, help is on its way!

Does your bra cup size change with your weight?

The primary reason for any changes in breast size (and therefore, cup size) is fat.

Fat can make up a good percentage of the breast structure.

So if that is altered, then it is easy to understand how it affects the breast itself.

Weight loss and age

Cup size changes depend on the amount of weight loss or gain, in addition to your age.

If you lose 7 to 14 lbs, chances are you won’t see much of a difference, unless you have a high proportion of breast fat.

If you lose or gain a significant amount, then you’re almost sure that your cup size will change too, whatever your age.

The older you are, the more fat you lose from your breast, and thus weight changes have a lesser impact.

Breast structure

The breast structure is made up of fat, glands and milk ducts, all held together by skin and connective tissue.

Those of us on the younger side have a higher ratio of glandular tissue to fat than older women.

This composition shifts with age due to estrogen levels falling during menopause.

Glandular and fat tissue diminishes, which really impacts our cup size when we lose weight.


We can’t instruct our body to lose fat where we would like (more’s the pity).

But we can work the underlying muscles to tone and support our body during our weight loss journey.

Target your pectoral muscles through body-weight exercises such as the bent-knee push-up and push-ups with single-leg raises.

The same with dumbbell exercises, presses, pullovers and the dumbbell fly.

Bra size measurement

Take bra size measurements once every four to 6 weeks as you lose weight, so that you’ll know if your bra size is changing.

Use a measuring tape to determine your chest measurement above your breasts and just under your arms.

Keep your arms at your side for precisions’ sake. After measuring the widest part of your bust line, deduct the first result.

Every inch in that result means one cup size, so a 1-inch difference means you have to go for an A cup, a 2-inch variable shows a B cup, etc.

If the numbers are the same, then you need an AA cup.

Tip: Which type of bra is best for a heavy breast? contains valuable information for ladies with large breasts who are looking for the most comfortable bra for plus-size women.

How weight impacts breast size

Weight loss or weight gain doesn’t affect cup size significantly, although it may differ from one person to another.

For some of us, a weight change of 25 pounds will make us go up or down a cup size, while a difference of 65 pounds might be needed to register the same change.

I hear you asking:

So what, exactly, is going to happen to our breasts?

You’re probably the best judge of that since you’re the one who knows your body best.

Do you see changes in your breasts when your weight changes? Are they the first place to be affected?

Of course, everyone sees changes according to their own body.

For example, with me, it’s all about the base! My bottom region is a good indicator if I’ve overindulged.

Does weight affect bra size? Conclusion

The structure of breasts isn’t the same for everyone.

Breasts are made up mostly of parenchyma (breast tissue), a layer of fat that differs in density, and skin.

You’re less likely to see changes in your breasts if they have a dense composition due to their tissue ratio, given that breast tissue itself doesn’t fluctuate in size.

Your breasts are more prone to change if their composition has a higher fat content.

In fact, your beautiful breasts are just like balloons…

Each time you increase air (put on weight) or deflate (reduce weight), the skin around your breast tissue loses more of its elasticity.

Hence the decrease in its ability to conform in tandem with your new breast shape.

Bonus tip

What bra style is best for big boobs? is an excellent resource for plus-size ladies wondering which type of bra might be a smart investment.

About Megan Smith

Megan has been fighting overweight and her plus size since her teenage years. After trying all types of remedies without success, she started doing her own research. Megan founded Plus Size Zeal to share her findings. She also developed various detailed buying guides for plus-size people in order to make their lives easier and more comfortable. Read More