Bra Size Calculator

How to Calculate Bra Size

The majority of women wear the wrong bra size—often without realizing it. Wearing the right size isn’t just about looks; it’s about comfort, health, and confidence.

Comfort and Posture

A well-fitting bra supports your bust and reduces strain on your back, shoulders, and neck. It improves posture and prevents pain caused by sagging or digging straps.

Breast Support and Health

Proper support reduces breast tissue stress, helps avoid long-term sagging, and enhances the performance of sports bras during physical activities.

Confidence and Body Shape

The right bra can enhance your silhouette, improve how your clothes fit, and boost self-esteem by making you feel secure and supported.

How Bra Sizes Work

Understanding bra sizing is key to getting the most accurate fit using our Bra Size Calculator.

Band Size vs Cup Size

• Band size (e.g., 32, 34, 36) measures the area under your bust.
• Cup size (e.g., A, B, C) measures the volume of your breasts relative to your band size.

Bra sizes combine these two elements—for example, 34C or 36B.

Sister Sizes Explained

Sister sizes are alternate bra sizes with the same cup volume but different band sizes. For example:

• 34C, 36B, and 32D are sister sizes.
  Understanding this helps when adjusting for tightness or cup fit.

How Our Bra Size Calculator Works

Our Bra Size Calculator is designed to deliver accurate sizing results based on two key measurements. No confusing conversions or fitting room struggles—just quick, reliable sizing.

Required Measurements

• Band size (underbust): Directly under the breasts
• Bust size (overbust): Around the fullest part of the bust

Step-by-Step Usage Instructions

1. Use a soft tape measure or string.
2. Measure your underbust and bust in inches or centimeters.
3. Enter the values into the calculator.
4. Click “Calculate” to receive your ideal bra size.

How It Determines Size and Fit

Our calculator:

• Calculates the band size based on underbust
• Calculates cup size difference (bust – band)
• Matches your result with international sizing charts for accuracy

Step-by-Step Guide to Measuring Yourself Accurately

Tools You Need

• A soft measuring tape
• A mirror (optional but helpful)
• A non-padded bra (optional for ease)

Measuring the Band Size

1. Wrap the tape around your rib cage, directly under the bust.
2. Keep the tape snug but not tight.
3. Round to the nearest whole number.

Measuring the Bust Size

1. Wrap the tape around the fullest part of your bust.
2. Ensure it’s level across your back.
3. Breathe normally and record the number.

Calculating the Cup Size

Subtract the band size from the bust measurement:

• 1 inch = A cup
• 2 inches = B cup
• 3 inches = C cup
  …and so on.

Bra Size Chart for Quick Reference

Band Size (inches)	Cup Size Difference (inches)	Resulting Cup Size
32	1″	A
32	2″	B
32	3″	C
34	2″	B
36	4″	D

Use this table to cross-check your calculator result, especially if in-between sizes.

Common Signs You’re Wearing the Wrong Bra Size

Straps Digging In or Slipping

If straps fall off or leave marks, it often means your band is doing too little or the cup isn’t right.

Gaping or Spilling Cups

Cups should lie flat. Gaps mean the cup is too big, spilling means it’s too small.

Pain or Discomfort

Back pain, shoulder pain, or pressure under the arms is often linked to incorrect sizing.

Benefits of Using Our Bra Size Calculator

Fast and Easy Sizing

No more guessing games or awkward fittings—just enter two numbers and get your perfect size.

Accurate Results Without a Fitting Room

Whether you’re at home, traveling, or shopping online, our tool gives tailored results instantly.

Better Shopping Confidence

Know your size before you shop. This saves time, prevents returns, and ensures you feel great in every purchase.

How Bra Size Varies Between Brands and Regions

US vs UK vs EU Sizing

• US and UK cup sizes align closely (e.g., 34C)
• EU uses centimeters for bands and alphabetical cup steps

Conversion Tips

Always refer to brand-specific size guides if you’re switching regions. A 75C in EU may be a 34C in the US.