Welcome to our comprehensive Bra Size Calculator, a tool designed to empower you with the knowledge to find a comfortable and supportive bra. We understand that navigating the world of bra sizing can be confusing and frustrating. With inconsistent sizing across brands and countries, finding the right fit often feels like a guessing game. An estimated 80% of women wear the wrong bra size, leading to discomfort, poor posture, and a lack of confidence. This tool was created to solve that problem.

Our calculator utilizes industry-standard measurement techniques, taking your unique underbust and bust measurements to provide a precise and reliable size recommendation. But we don’t stop there. We recognize that a single size doesn’t tell the whole story. That’s why our tool also provides your equivalent sizes in major international systems (US, UK, EU, AU) and introduces the concept of “sister sizes”—alternative sizes that may offer an even better fit depending on the bra’s style and brand. Our mission is to demystify bra sizing, providing you with a highly accurate starting point and the educational resources needed to make informed choices. Think of this tool not as a final answer, but as your expert guide on the journey to ultimate comfort and support.

Using our calculator is simple. Follow these steps for the most accurate results:

1. Prepare for Measurement: For best results, wear a lightly lined, non-padded bra. This ensures your breasts are held in a natural shape. Have a flexible measuring tape ready.
2. Select Your Unit: Use the dropdown at the top of the calculator to choose whether you’ll be measuring in Inches (in) or Centimeters (cm).
3. Measure Your Band (Underbust): Wrap the measuring tape snugly around your ribcage, directly underneath your bust. The tape should be parallel to the floor and level all the way around. Exhale to get the smallest possible measurement. Select this number in the “Underbust (Band) Measurement” dropdown.
4. Measure Your Bust: Wrap the measuring tape around the fullest part of your bust, usually at the nipple level. The tape should be comfortably loose, not digging into your breast tissue, and parallel to the floor. Select this number in the “Bust Measurement” dropdown.
5. Calculate: Click the “Calculate” button. Your results will instantly appear below, including your primary size, international conversions, and sister sizes. The charts at the top of the page will also update to reflect your data, providing a visual guide to how your size compares globally.
6. Reset: To start over or enter new measurements, simply click the “Reset” button.

Finding the right bra size is a game-changer for your comfort, posture, and confidence. A well-fitting bra doesn’t just look better under clothes; it provides essential support that can alleviate back, neck, and shoulder pain. Given that the vast majority of women are unknowingly wearing the wrong size, a reliable tool is more important than ever. Our calculator stands out by combining accuracy with education.

We provide a precise, data-driven starting point based on standard measurement formulas. But more importantly, we empower you with the knowledge to understand your results. The inclusion of international conversions and sister sizes transforms the calculator from a simple utility into a powerful shopping companion. You’ll learn not just *what* your size is, but *why* it might differ across brands and how to find viable alternatives. By using our calculator, you’re taking a proactive step towards better health, improved comfort, and the confidence that comes from a perfect fit.