How to Figure Out Your Bra Cup Size: An Expert Guide

How to Figure Out Your Bra Cup Size: An Expert Guide to the Perfect Fit

The right bra starts with the right size—and yet, over 80% of women are wearing the wrong one. A key part of unlocking true comfort and support is knowing your correct cup size. At Olivia Paisley Intimates, we specialize in helping women of all shapes and sizes feel confident in their fit, starting with accurate measurements and expert guidance.

Here’s everything you need to know about figuring out your bra cup size—at home or with a professional.

Why Cup Size Matters

Bra cup size is more than just a letter—it reflects the volume of your breasts in relation to your band size. Wearing the wrong cup size can lead to:

• Gapping or spillage in the cups

• Straps that dig in or slip off

• Back pain or poor posture

• A less flattering silhouette under clothing

Whether you’re shopping for a supportive everyday bra or something special and stylish, knowing your cup size ensures you get the fit and feel you deserve.

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

You’ll need:

• A soft measuring tape

• A mirror

• A non-padded bra or no bra (for best accuracy)

• A pen and paper—or this blog bookmarked 😊

Step 1: Measure Your Band Size (Underbust)

1. Stand straight and wrap the measuring tape firmly around your ribcage, right under your breasts.

2. Make sure the tape is level across your back.

3. Round to the nearest whole number.

4. Add 4 if the number is even, or 5 if it's odd.

Example: 31” underbust + 5 = 36 band size

Step 2: Measure Your Bust Size (Overbust)

1. Wrap the tape around the fullest part of your bust—usually across your nipples.

2. Don’t pull too tight; the tape should rest comfortably.

3. Round to the nearest whole number.

Example: Bust = 39”

Step 3: Calculate the Cup Size

Subtract your band measurement (Step 1 result) from your bust measurement (Step 2 result):

39” - 36” = 3”

Use the difference to find your cup:

Final bra size: 36C

Common Mistakes to Avoid

• Measuring over padded or push-up bras

• Pulling the tape too tightly (especially around the bust)

• Using a stretched-out or old bra for comparison

• Ignoring your body’s changes over time—always recheck your size every 6–12 months

Pro Tip: Sister Sizes Matter

If a certain size feels off, try its sister size. These are sizes with different bands and cups that carry similar volume.

For example:

• 34D → Sister sizes: 32DD or 36C

• 36C → Sister sizes: 34D or 38B

A proper fitting takes more than just numbers—it’s also about how the bra hugs your unique shape.

Get a Professional Fit at Olivia Paisley Intimates

Measuring at home is a great start, but nothing compares to an expert fitting. At Olivia Paisley Intimates, our trained fit specialists help you:

• Confirm your true size and shape

• Explore styles that flatter full busts, petite frames, and every body in between

• Discover comfortable, confidence-boosting bras that you’ll love to wear

Our boutique is designed to make every woman feel welcome, whether you’re just starting your lingerie journey or looking to elevate your collection.

Final Thoughts: A Better Fit Starts with Knowledge

Understanding how to figure out your bra cup size is an empowering first step toward loving the way you feel—every day. A well-fitting bra supports your body and enhances your confidence, inside and out.

Ready for your best fit yet?

👉 Visit Olivia Paisley Intimates for an in-store fitting or explore our expert-fit bras online. Because every woman deserves support that fits beautifully.