What Bra Size Is Jessica Chastain?

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Jessica Chastain is an award-winning American actress known for starring in movies with feminist themes. The Help, A Most Violent Year, and The Eyes of Tammy Faye are a few of her most recognizable films.

People still wonder about her bust measurements, as she is one of the most influential actresses in Hollywood. This is why I’m going to discuss Jessica Chastain’s bra size and how it relates to her breast shape.

What Bra Size Is Jessica Chastain?

Jessica Chastain has a bra size of 34B. She supports her 35- to 36-inch bust by wearing a bra with B cups. Her bra band varies in size from 30 to 32 inches.

Graphic image of Jessica Chastain with 34B bra size wearing a plunging blue lace dress

She has a round breast shape, putting equal breast tissue at the top and bottom. Having an hourglass body helps make Chastain’s bust look fuller. In contrast, American actresses like Brittany Snow who has a 34B bra size and Rashida Jones also has a 34B bra size, yet ther slim physique makes their bust look visually smaller.

Jessica Chastain can wear 32C and 36A as alternatives to her 34B bra size. She can share similar bra styles with fellow actress Lyndsy Fonseca, who wears a 32C bra. Contour and push-up bras are the best styles to make 34B breasts appear rounder.

Jessica Chastain Measurements

Jessica Chastain is average in height, measuring in at 5 feet 4 inches (5′ 4”). It’s estimated that her body measurements are 36-25-35 inches, which translates to a bust size of 36″, a waist size of 25″, and a hip size of 35”. She weighs roughly 123 pounds.

Benefits of Small Boobs

Minimal Bounce During Workouts

One huge benefit of having small breasts is that they hardly affect athletic performance because of their lack of bounce. It can be painful to have your boobs bouncing around as you work out, and women with small chests don’t have to experience this pain. Plus, small boobs mean you can wear pretty much any sports bra style, even if it has minimal padding.

Can Go Braless

One of the best things about being small-chested is that if you don’t want to wear a bra, you don’t have to! At their core, bras are meant to support your boobs, and when you are an A or B cup, you don’t need a bra for this purpose.

Little to No Sagging

Gravity is the enemy of breasts, especially since it can cause sagging. However, it won’t affect small boobs as much, and it’s unlikely for your small breasts to sag even when going braless. Whether you have A or B cup breasts, your boobs will look naturally firm and perky as you age.

Drawbacks of Small Boobs

Gaps Form Between Your Boobs and the Bra

When you have A-B sized breasts, it’s not uncommon for a gap to form between your chest and the bra you’re wearing. This is because your boobs are not large enough to fill the bra. Even if you try sizing down to a smaller bra, you might experience this issue.

Breasts Stay Small as You Gain Weight

If your breasts are dense with tissue, they won’t grow in size even as you gain weight. In turn, they may look significantly smaller as you gain more fat in other parts of your body. However, if you lose weight, the fat in your breasts may also reduce, causing your boobs to become even smaller.

Might Feel Self Conscious

It’s normal to feel self-conscious about having small breasts, particularly if you truly want to have large boobs. This can sometimes make you focus on looking for bras that can volumize your breasts regardless of the fit. However, small breasts can be as sexy as other breast sizes.

Bra Size Measurement & Cup Size | A, B, C, D, DD Bra Sizes AND Extra Large Breasts


The bra size of Jessica Chastain is 34B. This is among the smallest bra sizes, so it’s convenient to wear wireless bras. However, bras with contoured cups can help shape breast tissue.


Allena is the Founder and Editor of The Better Fit, a platform dedicated to empowering women with practical advice on bras and fitness, inspired by her own revelation of the widespread issue of incorrect bra sizing. Her expertise and tips have been recognized by major publications such as Cosmopolitan, Better Homes & Gardens, Insider, and NBC, making her a trusted voice in women's wellness and lifestyle.