Bra Cup Size Calculator
Finding the right bra size is crucial for comfort, support, and the overall look of your clothing. Many women wear the wrong bra size, leading to discomfort, poor posture, and an unflattering silhouette. This calculator helps you estimate your bra size based on two key measurements: your underbust and fullest bust.
How to Measure for Your Bra Size
To get the most accurate results from this calculator, follow these simple steps using a soft tape measure:
- Underbust Measurement (Band Size): Stand upright, exhale completely, and wrap the tape measure snugly around your rib cage, directly under your bust. Ensure the tape is level all the way around your back. This measurement helps determine your band size.
- Fullest Bust Measurement (Cup Size): Wrap the tape measure loosely around the fullest part of your bust, typically across your nipples. Make sure the tape is not too tight and is level across your back. This measurement, in combination with your underbust, determines your cup size.
It's best to take these measurements while wearing a non-padded bra or no bra at all for the most accurate results.
Understanding Bra Sizing Systems
Bra sizing isn't universal. Different regions use different systems, which can lead to confusion. This calculator provides estimates for three common systems:
- US Sizing: Often uses a "+4/5" method for band size (though modern methods are more direct) and a standard cup progression (A, B, C, D, DD, DDD, G, etc.).
- UK Sizing: Generally uses the actual underbust measurement for the band and a slightly different cup progression after D (D, DD, E, F, FF, G, GG, etc.). UK and US band sizes are often the same for smaller sizes.
- EU Sizing: Uses centimeters for band measurements, typically rounded to the nearest 5 cm (e.g., 70, 75, 80). The cup progression is also different (A, B, C, D, E, F, G, etc.).
Our calculator will provide an estimated size for each of these systems to give you a comprehensive understanding.
Inches
Centimeters
Important Considerations for Bra Fit
- Brand Variation: Just like clothing, bra sizes can vary between brands. Your calculated size is a starting point.
- Body Changes: Your bra size can change due to weight fluctuations, hormonal shifts, pregnancy, or aging. Re-measure periodically.
- Signs of a Good Fit: The band should be snug and level across your back, not riding up. The cups should fully encapsulate your breasts without gaping or spilling over. The center gore (the part between the cups) should lie flat against your sternum. Straps should provide minimal support, with most support coming from the band.
- Professional Fitting: For the most accurate and personalized recommendation, consider getting a professional bra fitting at a lingerie store.
Use this calculator as a guide to help you on your journey to finding the perfect fitting bra. Comfort and confidence start with the right foundation!
function calculateBraSize() { var underBustInput = parseFloat(document.getElementById("underBustMeasurement").value); var fullBustInput = parseFloat(document.getElementById("fullBustMeasurement").value); var unit = document.getElementById("unitSelection").value; if (isNaN(underBustInput) || isNaN(fullBustInput) || underBustInput <= 0 || fullBustInput <= 0) { document.getElementById("resultDisplay").innerHTML = "Please enter valid positive numbers for both measurements."; return; } if (fullBustInput <= underBustInput) { document.getElementById("resultDisplay").innerHTML = "Your Fullest Bust Measurement must be greater than your Underbust Measurement."; return; } var underBustInches = underBustInput; var fullBustInches = fullBustInput; var underBustCM = underBustInput; var fullBustCM = fullBustInput; if (unit === "Centimeters") { underBustInches = underBustInput / 2.54; fullBustInches = fullBustInput / 2.54; } else { // Assume Inches underBustCM = underBustInput * 2.54; fullBustCM = fullBustInput * 2.54; } // — US Sizing — // Modern US band sizing often rounds the underbust measurement to the nearest even number. var usBandSize = Math.round(underBustInches / 2) * 2; if (usBandSize < 28) usBandSize = 28; // Minimum common band size var usCupDifference = fullBustInches – usBandSize; var usCup = getUSCup(usCupDifference); // — UK Sizing — // UK band size is often the underbust measurement rounded to the nearest inch. var ukBandSize = Math.round(underBustInches); if (ukBandSize < 28) ukBandSize = 28; // Minimum common band size var ukCupDifference = fullBustInches – ukBandSize; var ukCup = getUKCup(ukCupDifference); // — EU Sizing — // EU band size rounds the underbust measurement in CM to the nearest multiple of 5. var euBandSize = Math.round(underBustCM / 5) * 5; if (euBandSize < 60) euBandSize = 60; // Minimum common band size var euCupDifferenceCM = fullBustCM – euBandSize; var euCup = getEUCup(euCupDifferenceCM); var resultHTML = "