How to Find Your True Bra Size: A Complete Sizing Guide

According to surveys by major apparel brands, up to **80% of women are wearing the wrong bra size**. The most common mistake is wearing a band that is too large and cups that are too small. This setup leads to poor support, neck and back fatigue, and discomfort throughout the day. Because brand sizing charts can feel inconsistent, knowing how to measure your own body is the key to finding a comfortable fit.

Calculating your bra size is simple once you have a flexible measuring tape and understand how the measurements translate to band sizes and cup letters. Here is our step-by-step guide to finding your true size using the standard UK sizing method.

Preparation

To get the most accurate results, you should: * Wear a non-padded, underwired bra that fits you reasonably well (do not measure over a sports bra, padded bra, or bare chest, as this will distort the shape). * Stand up straight, breathe normally, and keep the tape parallel to the floor during all measurements.

Step 1: Measure Your Underbust (Band Size)

Wrap the tape measure snugly around your ribcage, directly beneath your bust (where your bra band naturally sits).

• Write down the measurement in inches.
• Calculate Band Size: If the number is even, that is your band size. If it is odd, add 1 inch to find your band size (e.g., if you measure 31 inches, your band size is 32. If you measure 34 inches, your band size is 34).

Step 2: Measure Your Overbust (Cup Size)

Wrap the tape measure loosely around the fullest part of your bust (typically directly across the nipples). Do not pull the tape tight; it should rest gently against your chest.

• Write down the measurement in inches, rounding to the nearest whole number.

Step 3: Calculate the Difference

Subtract your calculated **Band Size** (from Step 1) from your **Overbust Measurement** (from Step 2). The difference determines your cup size letter:

• 0 inch difference = AA
• 1 inch difference = A
• 2 inch difference = B
• 3 inch difference = C
• 4 inch difference = D
• 5 inch difference = DD
• 6 inch difference = E
• 7 inch difference = F
• 8 inch difference = FF
• 9 inch difference = G

For example, if your Band Size is 34 and your Overbust is 37, the difference is 3 inches. Your calculated size is **34C**.

Signs of a Poor Fit

Check your current bra for these standard signs of an incorrect fit:

• Band Rides Up: If the back of your bra rides up toward your shoulder blades, the band is too large. A supportive band should remain level around your ribcage.
• Spillover (Quad-boob): If your breasts spill over the top or sides of the cups, the cup size is too small.
• Gaping Cups: If there is empty space at the top of the cups, the cup size is too large or the shape is incompatible.
• Digging Straps: If the shoulder straps dig into your skin, your band is likely too loose. The band should provide 80% of the bra's support, not the straps.