Bra Size Calculator & Converter - Sister Sizes & Fit Guide

Accurate bra size calculator & converter (US, UK, EU, AU). Find your exact cup size, sister sizes, and brand fitting while shopping.

Bra Size Calculator Chrome Extension the dedicated bra size calculator for Google Chrome. Install this free Chrome extension to calculate your bra size, find sister sizes, and convert US, UK, EU and AU sizes right from your browser toolbar. Looking for a bra size calculator Chrome extension? This is a lightweight, privacy-first browser extension that works offline in Chrome, with no website visits or sign-ups needed. Bra Size Calculator & Converter is the most accurate, privacy-first tool designed to help you calculate bra size, find sister sizes, and convert international measurements in seconds. Finding a bra that fits correctly is essential research reveals that over 80% of women wear the incorrect bra size. Whether you are shopping online or checking your current fit, this extension brings professional measurement analysis directly to your browser. Key Features & Measurement Capabilities: • Dual Mode Bra Measurement Calculator: Use the Quick Calculator for an instant check (snug underbust and standing bust) or toggle the accurate 6-point ABTF calculation method for complete ribcage and cup volume precision. • Automatic Sister Size Calculator: Instantly discover your equivalent sister sizes. If your band is riding up or digging in, switch between tighter band or looser band sister sizes without sacrificing cup volume. • International Bra Size Converter: Seamlessly convert bra sizes across US, UK, EU, and AU sizing standards. Effortlessly switch between inches and centimeters (CM). • Comprehensive Size Range: Supports band sizes 26 to 52 and cup sizes AA through N. • Brand-Specific Fit Guidance: Built-in sizing adjustments for popular lingerie systems, including Victoria's Secret, Skims, Calvin Klein, and Wacoal standards. • 100% Privacy Focused: Your underbust and bust measurements are calculated locally in your browser. Zero data tracking, zero storage. How to Use: 1. Select your unit (Inches or CM). 2. Input your underbust and bust measurements into the bra size calculator. 3. Click "Calculate Exact Bra Size" to view your recommended size, sister sizes, and global conversion charts. Eliminate fitting guesswork and find your true bra size with BreastCalculator.org.