Find Your Perfect Bra Fit
A well-fitting bra can transform your comfort and silhouette. Use this calculator to determine your recommended bra size based on two simple measurements. For best results, measure while wearing a non-padded bra or no bra at all.
.bra-fit-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 10px;
background-color: #ffffff;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
color: #333;
}
.bra-fit-calculator-container h2 {
text-align: center;
color: #6a0dad; /* A nice purple */
margin-bottom: 20px;
font-size: 1.8em;
}
.bra-fit-calculator-container p {
text-align: center;
margin-bottom: 25px;
line-height: 1.6;
color: #555;
}
.calculator-form .form-group {
margin-bottom: 20px;
}
.calculator-form label {
display: block;
margin-bottom: 8px;
font-weight: bold;
color: #444;
font-size: 1.1em;
}
.calculator-form input[type="number"] {
width: calc(100% – 20px);
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 1em;
box-sizing: border-box;
transition: border-color 0.3s ease;
}
.calculator-form input[type="number"]:focus {
border-color: #6a0dad;
outline: none;
box-shadow: 0 0 5px rgba(106, 13, 173, 0.3);
}
.calculator-form small {
display: block;
margin-top: 5px;
color: #777;
font-size: 0.9em;
}
.calculator-form button {
display: block;
width: 100%;
padding: 14px 20px;
background-color: #6a0dad;
color: white;
border: none;
border-radius: 6px;
font-size: 1.1em;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s ease, transform 0.2s ease;
margin-top: 25px;
}
.calculator-form button:hover {
background-color: #5a0b99;
transform: translateY(-2px);
}
.result-section {
margin-top: 30px;
padding: 20px;
border: 1px solid #dcdcdc;
border-radius: 8px;
background-color: #f9f9f9;
text-align: center;
min-height: 80px;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
}
.result-section p {
margin: 5px 0;
font-size: 1.1em;
color: #333;
}
.result-section strong {
color: #6a0dad;
font-size: 1.3em;
}
.result-section .error {
color: #d9534f;
font-weight: bold;
}
.result-section ul {
list-style-type: none;
padding: 0;
margin-top: 10px;
}
.result-section ul li {
margin-bottom: 5px;
color: #555;
}
function calculateBraSize() {
var underBustInput = document.getElementById("underBustMeasurement").value;
var fullBustInput = document.getElementById("fullBustMeasurement").value;
var braResultDiv = document.getElementById("braResult");
var underBustMeasurement = parseFloat(underBustInput);
var fullBustMeasurement = parseFloat(fullBustInput);
if (isNaN(underBustMeasurement) || isNaN(fullBustMeasurement) || underBustMeasurement <= 0 || fullBustMeasurement <= 0) {
braResultDiv.innerHTML = 'Please enter valid positive numbers for both measurements.';
return;
}
if (fullBustMeasurement < underBustMeasurement) {
braResultDiv.innerHTML = 'Your full bust measurement cannot be less than your underbust measurement. Please re-check your measurements.';
return;
}
// Step 1: Calculate Band Size
// Common method: If underbust is even, use it. If odd, add 1 to make it even.
// Then round to the nearest even number.
var bandSize = Math.round(underBustMeasurement / 2) * 2;
if (bandSize 0 (AA), 1-1.99 -> 1 (A), etc.
// Adjust for AA cup if difference is very small
if (cupDifference = 0) {
cupIndex = 0; // AA
} else if (cupDifference underBust, but for safety
} else {
cupIndex = Math.round(cupDifference);
}
if (cupIndex >= cupLetters.length) {
cupIndex = cupLetters.length – 1; // Cap at max defined cup
}
var recommendedCupSize = cupLetters[cupIndex];
var resultHTML = 'Your recommended bra size is:
' + bandSize + recommendedCupSize + '';
// Step 3: Calculate Sister Sizes
var sisterSizes = [];
// Sister size down (smaller band, larger cup)
var smallerBand = bandSize – 2;
var largerCupIndex = cupIndex + 1;
if (smallerBand >= 28 && largerCupIndex < cupLetters.length) {
sisterSizes.push(smallerBand + cupLetters[largerCupIndex]);
}
// Sister size up (larger band, smaller cup)
var largerBand = bandSize + 2;
var smallerCupIndex = cupIndex – 1;
if (largerBand = 0) { // Max common band size
sisterSizes.push(largerBand + cupLetters[smallerCupIndex]);
}
if (sisterSizes.length > 0) {
resultHTML += 'You might also try these "sister sizes" for a similar cup volume:';
resultHTML += '
';
for (var i = 0; i < sisterSizes.length; i++) {
resultHTML += '- ' + sisterSizes[i] + '
';
}
resultHTML += '
';
} else if (bandSize === 28 && cupIndex === 0) { // Smallest possible size
resultHTML += 'This is one of the smallest common sizes. You might find limited sister size options.';
} else if (bandSize === 50 && cupIndex === cupLetters.length -1) { // Largest possible size
resultHTML += 'This is one of the largest common sizes. You might find limited sister size options.';
}
braResultDiv.innerHTML = resultHTML;
}
Understanding Your Bra Size and Fit
Finding the right bra size is crucial for comfort, support, and the overall look of your clothes. Many women wear the wrong size, often due to outdated measuring methods or a lack of understanding of how bras should fit.
How to Measure Correctly:
- Underbust Measurement (Band Size): Stand upright, exhale, and wrap a soft measuring tape snugly around your rib cage, directly under your bust. Ensure the tape is level all the way around. This measurement helps determine your band size.
- Full Bust Measurement (Cup Size): Wrap the measuring tape loosely around the fullest part of your bust, usually over your nipples. Make sure the tape isn't too tight or too loose and is level.
Our calculator uses these two measurements to suggest a starting point for your bra size.
What Do the Numbers and Letters Mean?
- The Number (Band Size): This refers to the measurement around your rib cage. A well-fitting band should be snug and level all the way around your back, providing about 80% of the bra's support. If it rides up, it's too loose.
- The Letter (Cup Size): This indicates the difference between your full bust and band measurement. Each letter represents approximately a one-inch difference. The cup should fully encapsulate your breast tissue without gaping or spilling over.
Sister Sizes Explained
Sister sizes are bra sizes that have the same cup volume but a different band size. For example, a 34C, 32D, and 36B all have roughly the same cup volume. If your band feels too tight but the cups fit, you might try going up a band size and down a cup size (e.g., from 32D to 34C). Conversely, if the band is too loose but the cups fit, try going down a band size and up a cup size (e.g., from 34C to 32D).
Signs of a Poorly Fitting Bra:
- Band rides up: Too loose.
- Straps dig in: Often a sign the band isn't providing enough support, so you're over-tightening the straps.
- Cups gape: Cups are too big.
- Spillage (top or sides): Cups are too small.
- Center gore doesn't lie flat: Cups are too small or the style isn't right for your breast shape.
- Underwire pokes or digs: Cups are too small, or the wire isn't sitting correctly around your breast tissue.
Remember, bra sizing can vary slightly between brands and styles. This calculator provides a great starting point, but always try on bras to ensure the perfect fit for your unique body.