Building a Simple Interest Calculator with HTML, CSS, and JavaScript

Why I Built This I wanted to build another small front-end project that focuses on logic and clarity rather than features or design polish. An interest calculator felt like a good choice because it uses simple math but is still useful in real life. The goal was to practice writing clean JavaScript and building something understandable without frameworks. This is a learning-focused build log. What the Interest Calculator Does The calculator keeps things intentionally simple: Takes principal amount, interest rate, and time as input Calculates simple interest instantly Displays the result clearly Works well on mobile screens No charts, no compound logic, no advanced options. Tech Stack I intentionally kept the stack minimal: HTML – structure and input fields CSS – clean, responsive layout JavaScript – interest calculation and live updates Using vanilla JavaScript helped me focus on fundamentals instead of abstractions. Interest Calculation Logic The Formula (Plain English) Simple interest