Abstract: Disclosed herein is a chemistry and physics calculator for helping a user to solve chemistry and physics problems. The calculator does more than calculating numbers or solving equations; rather, the calculator includes an adaptable menu and sub-menu system that helps a user analyze a problem, determine the type of the problem, and helps a user choose equations that are needed to solve the problem. The calculator includes at least some of these topics: balancing equations, stoichiometry, gas laws, equilibrium, dimension analysis, electrochemistry, electricity, Newton laws, thermodynamics, properties of matter, mirrors and lenses, Ohm's law, and Kirchhoff's Law. Additionally, the calculator prompts users to input units for variables, performs unit analysis, and displays results with units. The invention can be implemented as a handheld calculator, as a computer program, or as a program for a handheld device such as a smart phone.