Find Your Perfect Fit: The Ultimate Bra Fit Calculator
Wearing the right bra size is transformative. It can improve your posture, alleviate back and shoulder pain, enhance your clothing's appearance, and boost your confidence. Yet, a staggering number of people wear the wrong bra size, often leading to discomfort and a less-than-ideal silhouette.
Our Bra Fit Calculator uses a comprehensive measurement method to help you determine your ideal bra size. By taking a few simple measurements, you can unlock a world of comfort and support you might not have known was possible.
Why Proper Bra Fit Matters
Comfort: A well-fitting bra won't dig, pinch, or ride up.
Support: The band, not the straps, should provide the majority of support, preventing strain on your shoulders and back.
Appearance: Clothes drape better, and your bust line is defined and lifted.
Health: Reduces potential for shoulder grooves, back pain, and skin irritation.
How to Measure for Your Bra Size Accurately
For the most accurate results, you'll need a soft measuring tape. Wear a non-padded, unlined bra or go braless. Stand in front of a mirror to ensure the tape is level. Take all measurements in inches.
Snug Underbust Measurement
Wrap the measuring tape directly under your bust, keeping it snug but not uncomfortably tight. Ensure the tape is level all the way around your back. Breathe normally. This measurement helps determine your band size.
Tight Underbust Measurement
Now, pull the tape as tight as possible, expelling all air from your lungs. This measurement helps confirm your band size and can indicate if you need to size down for a firmer band.
Standing Bust Measurement
Stand upright and measure around the fullest part of your bust. Ensure the tape is level across your back and not compressing your breast tissue. This is a primary measurement for cup size.
Leaning Bust Measurement
Lean forward 90 degrees (parallel to the floor). Measure around the fullest part of your bust while leaning. This helps capture breast tissue that might be compressed when standing, especially for fuller busts.
Lying Bust Measurement
Lie down on your back. Measure around the fullest part of your bust. This measurement helps account for breast tissue distribution when gravity is not a factor.
Enter these measurements into the calculator below to discover your recommended bra size!
Bra Fit Calculator
Enter your measurements in inches:
function calculateBraSize() {
var snugUnderbust = parseFloat(document.getElementById('snugUnderbust').value);
var tightUnderbust = parseFloat(document.getElementById('tightUnderbust').value);
var standingBust = parseFloat(document.getElementById('standingBust').value);
var leaningBust = parseFloat(document.getElementById('leaningBust').value);
var lyingBust = parseFloat(document.getElementById('lyingBust').value);
var resultDiv = document.getElementById('braFitResult');
resultDiv.innerHTML = "; // Clear previous results
// Input validation
if (isNaN(snugUnderbust) || isNaN(tightUnderbust) || isNaN(standingBust) || isNaN(leaningBust) || isNaN(lyingBust) ||
snugUnderbust <= 0 || tightUnderbust <= 0 || standingBust <= 0 || leaningBust <= 0 || lyingBust <= 0) {
resultDiv.innerHTML = 'Please enter valid positive numbers for all measurements.';
return;
}
// Ensure bust measurements are not less than underbust measurements
if (standingBust < snugUnderbust || leaningBust < snugUnderbust || lyingBust snugUnderbust) {
resultDiv.innerHTML = 'Your tight underbust measurement should not be greater than your snug underbust measurement. Please re-check your inputs.';
return;
}
// — Band Size Calculation —
// Band size is typically derived from the snug underbust measurement, rounded to the nearest even number.
var calculatedBand = Math.round(snugUnderbust);
if (calculatedBand % 2 !== 0) {
calculatedBand++; // Round up to the nearest even number if odd
}
var finalBandSize = calculatedBand;
var bandNotes = ";
// Consider the tight underbust for a potential alternative band size
var alternativeBand = Math.round(tightUnderbust);
if (alternativeBand % 2 !== 0) {
alternativeBand++;
}
// If the calculated band from snug is different from the band from tight, suggest trying the tighter one too.
if (finalBandSize !== alternativeBand && alternativeBand < finalBandSize) {
bandNotes = 'Your snug underbust suggests a ' + finalBandSize + ' band. However, your tight underbust of ' + tightUnderbust + ' inches suggests you might also try a ' + alternativeBand + ' band for a firmer fit, especially if you prefer a very snug band.';
}
// — Cup Size Calculation —
var averageBust = (standingBust + leaningBust + lyingBust) / 3;
var cupDifference = averageBust – snugUnderbust; // Use snug underbust for cup difference
var cupSizes = ['AA', 'A', 'B', 'C', 'D', 'DD/E', 'DDD/F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'];
var cupIndex = Math.round(cupDifference); // Each inch difference corresponds to a cup size
var recommendedCup = '';
if (cupIndex = cupSizes.length) {
recommendedCup = cupSizes[cupSizes.length – 1] + ' (or larger)';
} else {
recommendedCup = cupSizes[cupIndex];
}
// — Display Results —
var resultHTML = '
Your Recommended Bra Size:
';
resultHTML += " + finalBandSize + recommendedCup + ";
resultHTML += 'Based on your measurements, we recommend starting with a ' + finalBandSize + recommendedCup + '.';
resultHTML += 'How we calculated this:';
resultHTML += '
';
resultHTML += '
Your band size of ' + finalBandSize + ' is derived from your snug underbust measurement of ' + snugUnderbust + ' inches, rounded to the nearest even number.
';
resultHTML += '
Your average bust measurement is ' + averageBust.toFixed(1) + ' inches.
';
resultHTML += '
The difference between your average bust and snug underbust is ' + cupDifference.toFixed(1) + ' inches, which corresponds to a ' + recommendedCup + ' cup.
';
if (bandNotes) {
resultHTML += '
' + bandNotes + '
';
}
resultHTML += '
';
resultHTML += '
Important Fitting Tips:
';
resultHTML += '
';
resultHTML += '
The Band is Key: The band should be snug and level all the way around your back, not riding up. You should only be able to fit two fingers comfortably under the band at your back.
';
resultHTML += '
Cups Should Enclose: Your breasts should fully fill the cups without spilling over the top, sides, or bottom. There should be no gaping or wrinkling in the cups.
';
resultHTML += '
Gore Lies Flat: The center panel (gore) between the cups should lie flat against your sternum, without gapping or digging in.
';
resultHTML += '
Straps are Supportive, Not Sole Support: Straps should feel comfortable and not dig into your shoulders. They are there to keep the cups in place, not to provide primary support.
';
resultHTML += '
Try Different Styles: Bra styles vary. Your recommended size is a starting point; you may need to adjust cup or band size slightly depending on the brand and style.
';
resultHTML += '
Scoop & Swoop: When trying on a bra, lean forward and "scoop" all breast tissue from under your armpit and sides into the cups, then "swoop" it up.
';
resultHTML += '
';
resultHTML += 'Remember, this calculator provides a starting point. The best way to find your perfect bra is to try on different sizes and styles.';
resultDiv.innerHTML = resultHTML;
}
.bra-fit-article h2, .bra-fit-article h3, .bra-fit-article h4 {
color: #333;
margin-top: 1.5em;
margin-bottom: 0.8em;
}
.bra-fit-article p, .bra-fit-article ul, .bra-fit-article ol {
line-height: 1.6;
margin-bottom: 1em;
}
.bra-fit-article ul, .bra-fit-article ol {
margin-left: 20px;
}
.bra-fit-article li {
margin-bottom: 0.5em;
}
.bra-fit-calculator {
background-color: #f9f9f9;
border: 1px solid #ddd;
padding: 20px;
border-radius: 8px;
margin-top: 30px;
max-width: 600px;
margin-left: auto;
margin-right: auto;
}
.calculator-input-group {
margin-bottom: 15px;
}
.calculator-input-group label {
display: block;
margin-bottom: 5px;
font-weight: bold;
color: #555;
}
.calculator-input-group input[type="number"] {
width: calc(100% – 22px); /* Account for padding and border */
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
}
.bra-fit-calculator button {
background-color: #007bff;
color: white;
padding: 12px 20px;
border: none;
border-radius: 5px;
cursor: pointer;
font-size: 18px;
margin-top: 10px;
width: 100%;
box-sizing: border-box;
}
.bra-fit-calculator button:hover {
background-color: #0056b3;
}
.calculator-result {
margin-top: 25px;
padding: 15px;
border: 1px solid #e0e0e0;
border-radius: 6px;
background-color: #e9f7ff;
color: #333;
}
.calculator-result h3 {
color: #007bff;
margin-top: 0;
margin-bottom: 10px;
}
.calculator-result p {
margin-bottom: 8px;
}
.calculator-result ul {
margin-left: 20px;
margin-top: 10px;
}
.calculator-result li {
margin-bottom: 5px;
}
.bra-size-output {
font-size: 2em;
font-weight: bold;
color: #28a745; /* Green for emphasis */
text-align: center;
margin-bottom: 15px;
}