Find your estimated bra size by providing a few key measurements. Accurate measurements are crucial for a comfortable and supportive fit.
Standard/Full Coverage
Balcony/Half Cup
Push-Up
Longline
Your Estimated Bra Size:
Understanding Bra Sizing: A Comprehensive Guide
Choosing the right bra size is essential for comfort, support, and overall well-being. A well-fitting bra can improve posture, reduce back and shoulder pain, and prevent irritation. However, many women wear bras that are not the correct size, leading to discomfort and a lack of support.
This calculator provides an estimation of your bra size based on two primary measurements: your underbust and your overbust. While it offers a convenient starting point, remember that bra sizing can vary between brands and styles, and a professional fitting is always recommended for the most accurate result.
How the Calculation Works
The process involves two main steps:
Calculating the Band Size: The band size is primarily determined by your underbust measurement. This measurement should be taken snugly around your rib cage, directly under your breasts. The calculator converts this measurement into standard band sizes (e.g., 70, 75, 80, etc. in European sizing, or 32, 34, 36, etc. in US/UK sizing). The conversion typically involves rounding to the nearest standard band size. For instance, an underbust measurement of 73 cm might round up to a 75 band size.
Calculating the Cup Size: The cup size is determined by the difference between your overbust measurement (taken around the fullest part of your bust) and your underbust measurement. The overbust measurement should be taken loosely, allowing the tape to fit comfortably over the apex of your breasts. The difference between these two measurements indicates the volume of your breast tissue.
The Band and Cup Difference Chart
The following chart illustrates the typical differences that correspond to standard cup sizes. Note that these are general guidelines, and actual sizing can vary.
Note: Measurements are in centimeters (cm).
Difference (Overbust – Underbust)
European Cup Size
US/UK Cup Size (Approx.)
10-12 cm
A
AA/A
12-14 cm
B
B
14-16 cm
C
C
16-18 cm
D
D
18-20 cm
E
DD/E
20-22 cm
F
F
22-24 cm
G
G
The Role of Bra Style
Different bra styles are designed to provide varying levels of support and lift. The calculator considers your selected bra style as it can subtly influence the perceived fit and the best size for you:
Standard/Full Coverage: These bras offer maximum coverage and support, generally fitting true to size.
Balcony/Half Cup: Designed to lift and separate, these may require a slightly different fit.
Push-Up: These bras enhance cleavage and lift, potentially requiring a snugger band for optimal effect.
Longline: Extending further down the torso, longline bras offer broader support and may fit differently than traditional bras.
Why Accurate Sizing Matters
Wearing the correct bra size is not just about aesthetics; it's about health and comfort.
Support: The band of the bra should provide about 80% of the support. If the band is too loose, the bra won't lift effectively, and straps will dig in.
Comfort: An ill-fitting bra can cause chafing, pinching, and discomfort, affecting your daily activities.
Posture: Proper support from a well-fitting bra can contribute to better posture and reduce strain on your back and neck.
Breast Health: Reducing friction and providing adequate support can be beneficial for breast tissue health.
Tips for Measuring
Use a soft measuring tape.
Measure over bare skin or a thin, unpadded top.
Underbust: Breathe normally and measure snugly around your ribcage, just below your breasts. The tape should be level all around.
Overbust: Measure loosely around the fullest part of your bust, usually over the nipples. Ensure the tape is level and not digging in.
Check your current bra: Sometimes, the best indicator is a bra that currently fits well. Note its band and cup size.
Consider variations: Your size can change due to weight fluctuations, hormonal changes, and age.
While this calculator is a helpful tool, remember that individual body shapes and bra construction vary. For the most precise fit, we strongly recommend visiting a professional lingerie store for a bra fitting.
function calculateBraSize() {
var bandMeasurement = parseFloat(document.getElementById("bandMeasurement").value);
var bustMeasurement = parseFloat(document.getElementById("bustMeasurement").value);
var braStyle = document.getElementById("braStyle").value;
var resultElement = document.getElementById("result");
var braSizeResultElement = document.getElementById("braSizeResult");
var cupSizeTextElement = document.getElementById("cupSizeText");
// Clear previous results and hide the result section
braSizeResultElement.textContent = "";
cupSizeTextElement.textContent = "";
resultElement.style.display = "none";
// Validate inputs
if (isNaN(bandMeasurement) || bandMeasurement <= 0 || isNaN(bustMeasurement) || bustMeasurement <= 0) {
alert("Please enter valid positive numbers for both underbust and overbust measurements.");
return;
}
if (bustMeasurement <= bandMeasurement) {
alert("Your overbust measurement should be greater than your underbust measurement.");
return;
}
// — Band Size Calculation (European/International System) —
var bandSize;
// Simplified rounding for common band sizes (70, 75, 80, etc.)
// Add/subtract a small offset to align with typical rounding conventions for band sizes
var adjustedBandMeasurement = bandMeasurement + 1; // Example adjustment, might need tuning
if (adjustedBandMeasurement % 5 <= 2.5) { // Round down if remainder is less than or equal to 2.5
bandSize = Math.floor(adjustedBandMeasurement / 5) * 5;
} else { // Round up
bandSize = Math.ceil(adjustedBandMeasurement / 5) * 5;
}
// Ensure a minimum band size if calculations result too low
if (bandSize = 10 && difference = 12 && difference = 14 && difference = 16 && difference = 18 && difference = 20 && difference = 22 && difference = 24 && difference = 26 && difference = 28) {
cupSize = "J+"; // For larger differences
} else {
cupSize = "Cannot determine"; // For differences less than 10cm
}
// Adjust cup size based on bra style (simplified logic)
// This is a very basic adjustment; real-world adjustments are more nuanced.
// For example, push-up bras might feel better a cup size smaller, balcony a half-cup larger.
var adjustedCupSize = cupSize;
var adjustmentNote = "";
if (cupSize !== "Cannot determine" && cupSize !== "J+") {
if (braStyle === "pushup" && ["B", "C", "D", "E"].includes(cupSize)) {
// For push-up, suggest potentially trying a size down in cup
var cupIndex = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J+"].indexOf(cupSize);
if (cupIndex > 0 && cupIndex < 10) { // Avoid adjusting 'A' down or very large sizes
adjustedCupSize = ["A", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J+"][cupIndex – 1];
adjustmentNote = " (Consider trying one cup size smaller for push-up styles)";
}
} else if (braStyle === "balcony") {
// For balcony, sometimes a half-cup up can feel better depending on breast shape
// This is very approximate and subjective. We won't implement half-cups here for simplicity.
adjustmentNote = " (Balcony styles may fit differently; consider your usual fit)";
} else if (braStyle === "longline") {
adjustmentNote = " (Longline bras offer different support; consider your usual fit)";
}
}
// Display the result
braSizeResultElement.textContent = bandSize + adjustedCupSize;
cupSizeTextElement.textContent = "Based on your measurements, your estimated cup size is " + cupSize + "." + adjustmentNote;
resultElement.style.display = "block";
}