Meta Calculator > Learning Labs > How to Build Scientific Calculator > Online RPN Calculator

Reverse Polish Notation Calculator

This interactive online RPN calculator is meant to help you understand how RPN works in a calculator by illustrating how easy it is to use a stack to implement RPN. You can also download the Java source code here that has an RPN parser method. (Note the source code does not construct the front end of a scientific calculator, which is the easy part; instead, the code supports RPN parsing and also converting infix to postfix, the 2 more challenging parts of making a scientific calculator that supports the order of operations)

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Animation of Stack and RPN Calculations

The animation below shows you how a calculator would use a stack to store and evaluate the following rpn expression : 5 4 6 + /

The animation below walks you though an example of improper RPN syntax.