The Scientific Voice Calculator is a modern web-based application developed to combine traditional scientific calculation with advanced human–computer interaction. In today’s digital environment, users expect tools that are not only powerful but also intuitive and accessible. This project addresses that need by integrating scientific computation, calculus operations, graph plotting, and voice-based interaction into a single browser-based platform. Traditional calculators depend entirely on manual input using buttons or keyboards, which can create difficulties for users with physical disabilities, users who are multitasking, or learners who prefer more natural interaction with technology. The Scientific Voice Calculator overcomes these limitations by incorporating voice recognition technology through the Web Speech API. This allows users to perform calculations by simply speaking commands such as “calculate the integral of x squared” or “differentiate sin x.” The system processes the spoken input, performs the calculation, and provides both a visual result and an optional voice response using speech synthesis. The frontend of the application is developed using HTML5, CSS3, and JavaScript, ensuring compatibility across modern web browsers