Bras Size Calculator

Bra Size Calculator

Use this calculator to determine your estimated bra size based on two simple measurements. For best results, measure while wearing a non-padded bra or no bra at all.

function calculateBraSize() { var underBust = parseFloat(document.getElementById("underBustMeasurement").value); var bust = parseFloat(document.getElementById("bustMeasurement").value); var resultDiv = document.getElementById("braSizeResult"); if (isNaN(underBust) || isNaN(bust) || underBust <= 0 || bust <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for both measurements."; return; } if (bust < underBust) { resultDiv.innerHTML = "Your bust measurement cannot be smaller than your underbust measurement. Please re-measure carefully."; return; } // Step 1: Calculate Band Size (US/UK method) // Round underbust to nearest whole number var calculatedBand = Math.round(underBust); // If the rounded number is odd, add 1 to make it an even band size if (calculatedBand % 2 !== 0) { calculatedBand++; } // Ensure minimum common band size (e.g., 28) if (calculatedBand < 28) { calculatedBand = 28; } // Step 2: Calculate Cup Size var cupDifference = bust – calculatedBand; var cupSize = ""; // Assign cup letter based on inch difference if (cupDifference = 0.5 && cupDifference = 1.5 && cupDifference = 2.5 && cupDifference = 3.5 && cupDifference = 4.5 && cupDifference = 5.5 && cupDifference = 6.5 && cupDifference = 7.5 && cupDifference = 8.5 && cupDifference = 9.5 && cupDifference = 10.5 && cupDifference = 11.5 && cupDifference = 12.5 && cupDifference = 13.5 && cupDifference = 14.5 && cupDifference = 15.5 && cupDifference < 16.5) { // 15.5 to 16.49 inch difference cupSize = "P"; } else { cupSize = "P+ (Consult a specialist)"; } resultDiv.innerHTML = "

Your Estimated Bra Size:

" + "Band Size: " + calculatedBand + "" + "Cup Size: " + cupSize + "" + "Your estimated bra size is " + calculatedBand + cupSize + "." + "Note: Bra sizing can vary between brands and regions. This is an estimate based on common US/UK sizing conventions. Always try on bras to confirm the best fit."; }

Understanding Bra Sizing: A Comprehensive Guide

Finding the perfect bra can be a transformative experience, offering comfort, support, and confidence. However, with so many styles and sizing systems, it's common for many individuals to wear the wrong bra size. This guide will help you understand the fundamentals of bra sizing and how to use our calculator effectively.

Why Accurate Bra Sizing Matters

Wearing a bra that doesn't fit correctly can lead to a host of issues, including:

• Discomfort: Digging straps, a riding-up band, or cups that gape or overflow.
• Poor Support: Leading to back, neck, and shoulder pain, especially for those with larger busts.
• Altered Posture: Incorrect support can affect your posture over time.
• Clothing Fit: A well-fitting bra enhances the look of your clothes.
• Breast Health: While not directly linked to serious health issues, proper support can prevent discomfort and tissue stretching.

How to Measure for Your Bra Size

For the most accurate results, measure yourself while wearing a non-padded bra or no bra at all. Use a soft measuring tape and stand in front of a mirror if possible.

1. Underbust Measurement (Band Size)

This measurement determines your band size. It should be taken snugly around your rib cage, directly under your bust. Ensure the tape measure is level all the way around your back and parallel to the floor. Breathe out to get the smallest measurement. This is your Underbust Measurement.

Example: If your snug underbust measurement is 30.5 inches.

2. Bust Measurement (Cup Size)

This measurement determines your cup size. Measure around the fullest part of your bust, usually across the nipple line. Make sure the tape measure is not too tight and doesn't compress your breasts. Again, ensure the tape is level all the way around your back. This is your Bust Measurement.

Example: If your fullest bust measurement is 36 inches.

How the Calculator Works (US/UK Sizing)

Our calculator uses a widely accepted method for determining US/UK bra sizes:

1. Band Size: Your snug underbust measurement is rounded to the nearest whole number. If this number is odd, one inch is added to make it an even number. This even number becomes your band size (e.g., 28, 30, 32, etc.). This method aims to ensure the band, which provides 80-90% of the bra's support, fits snugly.
2. Cup Size: The difference between your fullest bust measurement and your calculated band size determines your cup letter. Each inch of difference typically corresponds to one cup size (e.g., 1 inch difference = A cup, 2 inches = B cup, and so on).

Example Calculation

Let's use the example measurements:

• Underbust Measurement: 30.5 inches
• Bust Measurement: 36 inches

Step 1: Calculate Band Size

• Underbust: 30.5 inches
• Rounded to nearest whole: 31 inches
• Since 31 is odd, add 1: 32 inches
• Calculated Band Size: 32

Step 2: Calculate Cup Size

• Bust Measurement: 36 inches
• Calculated Band Size: 32 inches
• Difference: 36 – 32 = 4 inches
• 4 inches difference corresponds to a D cup.

Estimated Bra Size: 32D

Tips for Finding Your Best Fit

• The Band is Key: The band should be snug and level all the way around your back, not riding up. You should be able to fit two fingers comfortably under the band at your back.
• Cups Should Enclose: Your breasts should fill the cups without gaping or spilling over at the top, sides, or bottom.
• Straps are for Support, Not Lift: Straps should feel comfortable and not dig into your shoulders. They provide about 10-20% of the support; the band does the rest.
• Center Gore Lays Flat: The center panel (gore) between the cups should lie flat against your sternum.
• Try Sister Sizes: If your calculated size isn't quite right, try "sister sizes." These have the same cup volume but different band sizes. For example, if you're a 34C, your sister sizes are 32D (smaller band, larger cup letter) and 36B (larger band, smaller cup letter).
• Different Brands, Different Fits: Just like clothing, bra sizing can vary between brands. Use this calculator as a starting point, but always try on bras to find the perfect fit.

Remember, finding the right bra size is a journey. Don't be discouraged if it takes a few tries. Comfort and support are paramount!