An online calculator is a digital tool that allows users to perform mathematical calculations directly through a web browser. These calculators can handle basic arithmetic operations like addition, subtraction, multiplication, and division, as well as more complex functions such as square roots and percentages. They are accessible from various devices, including computers, tablets, and smartphones. Many online calculators also offer specialized functions for specific fields, such as finance, statistics, and engineering. Users can find calculators for tasks like loan calculations, unit conversions, and graphing equations. Overall, online calculators provide a convenient way to solve math problems without needing physical tools or software installations.