What Bra Size Is Katharine McPhee?

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Katharine McPhee is an American singer-songwriter and actress. She is best known for her appearances in American Idol, Smash, and Scorpion.

She is vocal about her experience of loving her body early as a teenager when she started modeling. This includes being confident with her measurements, which is why I’m going to discuss Katharine McPhee’s bra size, along with its pros and cons.

What Bra Size Is Katharine McPhee?

Katharine McPhee has a bra size of 34B. This indicates her bust measures 35 to 36 inches. She needs to wear a bra with B cups and a band ranging from 30 to 32 inches.

Graphic image of Katharine McPhee with 34B bra size wearing a spaghetti strap blouse and red skirt

Actresses in their late 30s with an hourglass body typically have 34B breasts. For instance, actress Megan Fox also has a 34B bra size. This bra size and body figure feature a small waist and a wide bust.

Katharine McPhee can sister size to 32C and 36A. This implies she can share bra styles with singer Piper Rockelle, who wears a 32C bra size. While McPhee won’t have to worry about back bra bulges, she may struggle to find a sports bra that won’t flatten her breasts.

Benefits of a Small Chest

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 a minimal lining or unlined bras.

Can Easily Wear Low Cut Shirts

Women with smaller boobs can get away with taping their breasts to wear deep plunging dresses. Even if you are dancing or jumping around, your breasts won’t show through a wrap dress, a scoop-neck tank top, or a V-neck camisole.

Don’t Have Back Pain

Ladies blessed with small breasts can avoid the dreaded back pain. Breast weight can cause your shoulders to move forward, which forces the muscles in your back and shoulder blades to adjust. Having less weight in front means your torso can easily carry your breasts, and the weight doesn’t need to be redistributed.

Drawbacks of a Small Chest

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 such as push up bras for small breasts. However, small breasts can be as sexy as other breast sizes.

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.

Don’t Always Fill Out Clothing

Despite its several benefits, among the most notable disadvantages of having small breasts is the chance that you won’t fill out bra cups or clothing. Particularly when the breast tissue is leaning toward the bottom, the shallow bustline can cause gaping cups.

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


Katharine McPhee has a 34B bra size. While this is generally a small size among women, her breasts look more prominent because of her small waist. This lets her show off her bust using strapless, demi, and plunge bras.


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.