Get an accurate bra size estimate by measuring your band and bust. Enter your measurements in inches.
Your Estimated Bra Size
Enter measurements to see result
Understanding Bra Sizing
Finding the right bra size is crucial for comfort, support, and overall well-being. The most common method for determining bra size involves two key measurements: the band size and the cup size. This calculator uses a standard method to help you estimate your size.
How the Calculation Works:
Band Measurement: This is the measurement around your rib cage, directly under your bust. It provides the foundation and support for the bra. The number in your bra size (e.g., 34 in 34B) corresponds to this measurement, often rounded to the nearest even number.
Bust Measurement: This is the measurement around the fullest part of your bust, usually over the nipples.
Cup Size Calculation: The cup size is determined by the difference between your bust measurement and your band measurement. The formula typically used is:
Cup Size = Bust Measurement - Band Measurement
Once you have this difference (in inches), it's converted into a letter size:
0-1 inch difference = AA cup
1 inch difference = A cup
2 inch difference = B cup
3 inch difference = C cup
4 inch difference = D cup
5 inch difference = DD (or E) cup
And so on, with each additional inch typically representing the next letter in the alphabet (F, G, H, etc.).
Important Considerations:
While this calculator provides a good starting point, remember that bra sizing can vary between brands and styles. Factors such as the bra's construction, fabric, and intended support level can affect fit.
Body Shape: Different body shapes might require adjustments.
Bra Style: T-shirt bras, push-up bras, and sports bras can fit differently.
Brand Variations: Sizes are not always consistent across all manufacturers.
We highly recommend trying on bras after using this calculator to ensure the perfect fit. Sometimes, a slight adjustment in band or cup size might be necessary for optimal comfort and support.
function calculateBraSize() {
var bandMeasurement = parseFloat(document.getElementById("bandMeasurement").value);
var bustMeasurement = parseFloat(document.getElementById("bustMeasurement").value);
var resultDiv = document.getElementById("braSizeResult");
var bandResultDiv = document.getElementById("braBandResult");
var cupResultDiv = document.getElementById("braCupResult");
resultDiv.innerHTML = ";
bandResultDiv.innerHTML = ";
cupResultDiv.innerHTML = ";
if (isNaN(bandMeasurement) || isNaN(bustMeasurement) || bandMeasurement <= 0 || bustMeasurement <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for measurements.";
return;
}
if (bustMeasurement <= bandMeasurement) {
resultDiv.innerHTML = "Bust measurement must be larger than band measurement.";
return;
}
// Determine Band Size
var bandSizingMap = [
{ maxDiff: 1, size: "30" },
{ maxDiff: 3, size: "32" },
{ maxDiff: 5, size: "34" },
{ maxDiff: 7, size: "36" },
{ maxDiff: 9, size: "38" },
{ maxDiff: 11, size: "40" },
{ maxDiff: 13, size: "42" },
{ maxDiff: 15, size: "44" },
{ maxDiff: 17, size: "46" }
];
var roundedBand = Math.round(bandMeasurement / 2) * 2; // Round to nearest even number
var bandSize = roundedBand;
bandResultDiv.innerHTML = "Estimated Band Size: " + bandSize;
// Determine Cup Size
var cupDifference = bustMeasurement – bandMeasurement;
var cupSize = "";
if (cupDifference = 1 && cupDifference = 2 && cupDifference = 3 && cupDifference = 4 && cupDifference = 5 && cupDifference = 6 && cupDifference = 7 && cupDifference = 8 && cupDifference = 9 && cupDifference = 10 && cupDifference < 11) cupSize = "J";
else cupSize = "K+"; // For larger differences
cupResultDiv.innerHTML = "Estimated Cup Size: " + cupSize;
resultDiv.innerHTML = bandSize + cupSize;
}