USA Bra Size Calculator: Find Your Perfect Fit
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. Our USA Bra Size Calculator helps you determine your correct bra size based on standard American sizing conventions.
Why Bra Size Matters
A well-fitting bra can make a significant difference in your daily life. It provides proper support, reduces back and shoulder pain, and enhances your natural shape. Conversely, an ill-fitting bra can cause digging straps, gaping cups, spillage, and general discomfort.
How to Measure for Your Bra Size
To use this calculator accurately, you'll need a soft measuring tape. Wear a non-padded bra or no bra at all for the most precise measurements. Follow these two simple steps:
- Snug Underbust Measurement: Wrap the measuring tape snugly around your rib cage, directly under your bust. Make sure the tape is level all the way around and exhale to get the smallest measurement. This measurement helps determine your band size.
- Fullest Bust Measurement: Wrap the measuring tape loosely around the fullest part of your bust, usually across the nipples. Ensure the tape is level and not too tight or too loose. This measurement helps determine your cup size.
Enter these measurements in inches into the calculator below.
USA Bra Size Calculator
Understanding Your Bra Size
Your bra size consists of two parts: a number (the band size) and a letter (the cup size). The band size corresponds to your underbust measurement, while the cup size is determined by the difference between your fullest bust and band measurements.
- Band Size: Provides the primary support for your breasts. It should fit snugly around your rib cage without digging in or riding up.
- Cup Size: Holds your breast tissue. The cups should fully encapsulate your breasts without gaping or spillage.
Examples of Bra Size Calculation
Let's walk through a couple of examples to illustrate how the calculator works:
Example 1:
- Snug Underbust: 31.5 inches
- Fullest Bust: 37 inches
- Calculation:
- Band Size: 31.5 inches rounds to 32 (nearest even number).
- Cup Difference: 37 (Fullest Bust) – 32 (Calculated Band) = 5 inches.
- Cup Size for 5 inches difference = DD.
- Result: 32DD
Example 2:
- Snug Underbust: 34 inches
- Fullest Bust: 36 inches
- Calculation:
- Band Size: 34 inches (already an even number).
- Cup Difference: 36 (Fullest Bust) – 34 (Calculated Band) = 2 inches.
- Cup Size for 2 inches difference = B.
- Result: 34B
Tips for a Perfect Fit
- Try it on: Always try on bras before purchasing. Sizes can vary slightly between brands.
- Check the band: The band should be level all the way around your back and snug enough that you can only fit two fingers underneath it.
- Check the cups: There should be no gaping or spillage. Your breast tissue should be fully contained within the cups.
- Check the straps: Straps should provide minimal support; the band does most of the work. They should not dig into your shoulders.
- Center gore: The center panel between the cups (gore) should lie flat against your sternum.
Use this calculator as a starting point, and remember that personal comfort is key. Happy bra shopping!
function calculateBraSize() { var snugUnderbustInput = document.getElementById("snugUnderbust").value; var fullestBustInput = document.getElementById("fullestBust").value; var snugUnderbust = parseFloat(snugUnderbustInput); var fullestBust = parseFloat(fullestBustInput); var resultDiv = document.getElementById("result"); if (isNaN(snugUnderbust) || isNaN(fullestBust) || snugUnderbust <= 0 || fullestBust <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for both measurements."; return; } // Calculate Band Size (USA method: round to nearest even number) var bandSize = Math.round(snugUnderbust / 2) * 2; // Ensure minimum band size is reasonable, e.g., 28 or 30 if (bandSize < 28) { bandSize = 28; // A common minimum band size in USA } // Calculate Cup Size var cupDifference = fullestBust – bandSize; var cupSize = ""; if (cupDifference = 0 && cupDifference = 1 && cupDifference = 2 && cupDifference = 3 && cupDifference = 4 && cupDifference = 5 && cupDifference = 6 && cupDifference = 7 && cupDifference = 8 && cupDifference = 9 && cupDifference = 10 && cupDifference = 11 && cupDifference < 12) { cupSize = "K"; } else { cupSize = "L or larger (consult a specialist)"; } resultDiv.innerHTML = "Based on your measurements:" + "Calculated Band Size: " + bandSize + " inches" + "Calculated Cup Size: " + cupSize + "" + "Your Estimated USA Bra Size: " + bandSize + cupSize; }