What Size Bra Am I? Here’s the Truth Most Lingerie Stores Don’t Tell You

If you’ve ever asked yourself, “What size bra am I?”, you’re not alone—and you’re certainly not the only one who’s gotten it wrong.

An estimated 80% of women wear the wrong bra size, often because traditional sizing methods are outdated, inconsistent, or miscommunicated. The truth is: the right bra size can transform how your clothes fit, how you carry yourself, and how you feel in your own skin.

As lingerie professionals, we’re here to help you decode the numbers and letters on the tag and guide you to your real bra size—with expert precision and zero guesswork.

Why Bra Sizing is More Complicated Than It Looks

Contrary to popular belief, bra sizing is not just about small, medium, or large. It’s a two-part equation:

• Band Size (e.g., 32, 34, 36): The measurement around your ribcage, directly under your bust.

• Cup Size (e.g., B, DD, G): The volume of your breasts in relation to your band size.

This means that a 34D is not the same cup size as a 38D. In fact, cup size is relative to the band. This is where many people go wrong—and why “sister sizing” matters.

Step-by-Step: How to Measure Your Bra Size at Home

Here’s how to get an accurate measurement using just a soft measuring tape and a mirror.

✅ Step 1: Measure Your Band Size

• Stand straight, wear a non-padded bra or no bra.

• Wrap the measuring tape snugly around your ribcage, just under your breasts.

• Round down to the nearest even number (e.g., 31” = 30 band).

✅ Step 2: Measure Your Bust Size

• Wrap the tape around the fullest part of your bust, keeping it level and not too tight.

• Round to the nearest whole number.

✅ Step 3: Calculate Your Cup Size

Subtract your band size from your bust measurement. The difference determines your cup size.

Example:
Bust: 37"
Band: 32"
37 - 32 = 5 → 32DD (or E in European sizing)

Understanding Sister Sizing

If your perfect size isn’t available, try a sister size—a size with the same cup volume but a different band.

• Going down a band size? Go up a cup (e.g., 34D → 32DD)

• Going up a band size? Go down a cup (e.g., 32DD → 34D)

This can help you find a better fit if a bra feels too tight in the band or too loose in the cups.

Signs You're Wearing the Wrong Bra Size

If you're constantly adjusting your straps, feeling poked by underwires, or spilling out of your cups, chances are you’re in the wrong size. Watch out for:

• Band riding up your back → band too loose

• Cup spillage or gaping → wrong cup size

• Straps digging in → band isn’t offering enough support

• Underwire sitting on breast tissue → cup too small or wrong shape

Fit First, Then Style

Once you find your correct size, the right bra shape can make a world of difference depending on your breast shape, spacing, and clothing preferences:

• T-shirt Bra: Seamless and great for everyday wear

• Balconette Bra: Ideal for wide-set or shallow breasts

• Plunge Bra: Great for deep necklines and close-set breasts

• Full Coverage Bra: Best for larger cup sizes or minimizing bounce

A Note on Vanity Sizing and Brand Variability

Just like jeans, bras vary by brand and region. A 34D in one brand may fit more like a 32DD in another. That’s why trying on bras—or shopping with brands that offer generous exchange policies—is crucial.

Brands like Panache, Natori, ThirdLove, Chantelle, and Elomi are known for their consistency and extended sizing.

Final Thoughts: Your Bra Size Is a Tool, Not a Label

Knowing your real bra size is about more than a number and a letter. It’s about choosing a garment that supports your posture, enhances your silhouette, and honors your body. Whether you have full breasts, asymmetry, wide-set spacing, or large tits (yes, let’s use the real language), you deserve a bra that fits you—not one you settle for.

Expert Tip: Get re-measured or measure yourself every 6–12 months. Hormones, weight changes, pregnancy, and even your fitness routine can affect your size.