QubitGuardx is a next-generation quantum cryptography calculator that transforms complex Quantum Key Distribution (QKD) security models into an intuitive, interactive tool. By combining photon loss, detector performance, dark counts, and error correction overhead into a unified calculation, it delivers instant insights on secure key rates and Quantum Bit Error Rate (QBER). Designed with researchers, engineers, and learners in mind, the app provides a visually refined interface and accurate results to help users evaluate system reliability, optimize designs, and strengthen the foundation of quantum-safe communication.