MultiplexCalc is a multipurpose and comprehensive desktop calculator for Windows. It is small and simple to use but with much power and versatility underneath. It can be used as an enhanced elementary, scientific, financial or expression calculator. MultiplexCalc contains more than hundred internal constants and functions (algebraic, trigonometric, hyperbolic, transcendental, etc;) to satisfy your needs to solve problems ranging from simple elementary algebra to complex equations. Its underling implementation encompasses high precision, sturdiness and multi-functionality.  MultiplexCalc also has the unlimited ability to extend itself by using user-defined variables. You can add your own variables to MultiplexCalc in order to convenience your work. Any instance of a formula can be parsed once, and calculated many times with different variable values.