Bra Size Calculation

Bra Size Calculator

Use this calculator to estimate your bra size based on your underbust and bust measurements. Please measure in inches for the most accurate results with this calculator's US/UK sizing system.

function calculateBraSize() { var underBust = parseFloat(document.getElementById("underBustMeasurement").value); var bust = parseFloat(document.getElementById("bustMeasurement").value); var resultDiv = document.getElementById("braSizeResult"); if (isNaN(underBust) || isNaN(bust) || underBust <= 0 || bust <= 0) { resultDiv.innerHTML = "Please enter valid positive numbers for both measurements."; return; } if (bust <= underBust) { resultDiv.innerHTML = "Bust measurement must be greater than underbust measurement."; return; } // Calculate Band Size (US/UK method: round underbust to nearest even number) var bandSize = Math.round(underBust); if (bandSize % 2 !== 0) { bandSize++; // Round up to the next even number if odd } if (bandSize < 28) { // Minimum common band size bandSize = 28; } // Calculate Cup Difference var cupDifference = bust – bandSize; // Difference between bust and calculated band // Determine Cup Letter var cupLetter = ""; if (cupDifference underbust, but as a safeguard } else if (cupDifference >= 0 && cupDifference = 1 && cupDifference = 2 && cupDifference = 3 && cupDifference = 4 && cupDifference = 5 && cupDifference = 6 && cupDifference = 7 && cupDifference = 8 && cupDifference = 9 && cupDifference < 10) { cupLetter = "I"; } else { cupLetter = "J+ (consult a specialist)"; } resultDiv.innerHTML = "Your estimated bra size is: " + bandSize + cupLetter + " (US/UK Sizing)"; }

Understanding Bra Size and How to Measure

Finding the right bra size is crucial for comfort, support, and overall breast health. A well-fitting bra can improve posture, alleviate back and shoulder pain, and enhance the appearance of your clothing. Conversely, a poorly fitting bra can lead to discomfort, skin irritation, and inadequate support.

The Two Key Measurements: Band and Bust

Bra sizing is based on two primary measurements:

1. Band Size: This measurement determines the numerical part of your bra size (e.g., 32, 34, 36). It's taken around your rib cage, directly under your bust.
2. Bust Size: This measurement determines your cup letter (e.g., A, B, C). It's taken around the fullest part of your bust.

How to Measure Yourself Accurately

For the most accurate results, wear a non-padded bra or no bra at all. Use a soft measuring tape and stand in front of a mirror.

• For Underbust Measurement (Band Size):

  Wrap the measuring tape snugly around your rib cage, directly under your bust. Ensure the tape is level all the way around your back. Exhale to get the smallest possible measurement. This calculator will then round this number to the nearest even whole number to determine your band size (e.g., 30.5 inches rounds to 30, 31 inches rounds to 32).

• For Bust Measurement (Cup Size):

  Wrap the measuring tape loosely around the fullest part of your bust, usually across the nipples. Make sure the tape is level and not too tight or too loose. This measurement, in conjunction with your calculated band size, will determine your cup letter.

Understanding the Calculation (US/UK Sizing)

This calculator uses a common US/UK sizing method:

1. Band Size: Your underbust measurement is rounded to the nearest even whole number. For example, if your underbust is 30.5 inches, your band size will be 30. If it's 31 inches, your band size will be 32.
2. Cup Size: The difference between your bust measurement and your calculated band size determines your cup letter. Each inch of difference typically corresponds to one cup size:
   • Less than 1 inch: AA
   • 1 inch: A
   • 2 inches: B
   • 3 inches: C
   • 4 inches: D
   • 5 inches: DD/E
   • 6 inches: DDD/F
   • And so on…

Examples:

• Example 1:

  Underbust: 30.5 inches
  Bust: 36 inches
  Calculated Band: 30 (30.5 rounded to nearest even)
  Cup Difference: 36 – 30 = 6 inches
  Estimated Bra Size: 30DDD/F

• Example 2:

  Underbust: 31 inches
  Bust: 34 inches
  Calculated Band: 32 (31 rounded up to nearest even)
  Cup Difference: 34 – 32 = 2 inches
  Estimated Bra Size: 32B

• Example 3:

  Underbust: 34 inches
  Bust: 37 inches
  Calculated Band: 34 (already even)
  Cup Difference: 37 – 34 = 3 inches
  Estimated Bra Size: 34C

Important Considerations:

While this calculator provides a good starting point, bra sizing can be complex due to variations between brands and different international sizing systems (e.g., EU, French, Australian). This calculator focuses on a common US/UK sizing method.

The best way to confirm your bra size is always to try on bras. Look for a band that feels snug and level, cups that don't gap or overflow, and straps that provide support without digging in. Don't hesitate to seek a professional bra fitting for personalized advice.