Scientific Calculator for fx-991EX and fx-115ES PLUS
CalcES puts an advanced scientific calculator on your screen for free. Choose the fx-991EX keypad for the functions you know, the ES PLUS keypad if you learned on an fx-115ES PLUS, or the CW-style keypad for an fx-9910CW. Fractions, roots and equations appear in the same textbook-style notation you use in class.
From Algebra II to college STEM
When an Algebra II problem moves from fractions to a quadratic equation, you can keep the expression in one place and inspect the result as a fraction or decimal. In pre-calculus, use degrees or radians for trigonometry and switch the angle unit to match the assignment. For calculus, enter a derivative at a point, a definite integral or a limit without flattening the notation into a line of text.
College physics and engineering work often calls for more than a single answer. Store values for later calculations, return to a previous line in the history, and choose scientific or engineering notation for a result with a large exponent. The named constants include Planck's constant and the speed of light. For derivatives and integrals, compare the calculator's result with the relevant rule in your course notes when the method matters.
The 991, 115 and CW keypads
The 991 family includes several different keypad generations. CalcES offers an EX-style keypad for the fx-991EX, an ES PLUS-style keypad for the fx-115ES PLUS, and a ClassWiz CW-style keypad for the fx-9910CW. Each board gives you the familiar key positions and way of entering fractions, trigonometry and equations. Select the family that matches your handheld and practise in the layout you know.
CalcES is an independent MathDa product. It is not affiliated with or endorsed by Casio. Casio and the model names mentioned here are trademarks of their respective owners.
Matrices and complex numbers
For a linear algebra assignment, build a matrix and ask for its determinant, inverse or transpose. When you need to inspect the structure of a system, row reduction and other matrix operations are available too. You can also work with complex numbers and convert between rectangular and polar forms, a useful check while studying circuits and waves.
The calculator can solve equations and systems as well as evaluate expressions. For a worked explanation of a supported problem, open the built-in Tales Math Solver from a result. It opens beside the keypad on a larger screen and as a sheet on a phone, so you can compare your calculation with the steps.
See the shape of an answer
Numbers do not always tell you where a function turns or two curves meet. Send a result to the Graph tab, or open the graphing calculator to plot a function, equation or inequality. Tap a curve to inspect crossings and intersections, then drag along it to read coordinates. This is useful when a pre-calculus or college STEM problem asks you to connect an algebraic result with a graph.
Frequently asked questions
Does CalcES work like an fx-991EX, fx-115ES PLUS or fx-9910CW?
CalcES supports the EX, ES PLUS and CW families with familiar keys for fractions, trigonometry, equations and other everyday calculations. Choose the family your handheld belongs to and use the layout you know. CalcES is independent and is not affiliated with Casio.
Can I use this website in an exam room?
No. Use CalcES to practise beforehand. Follow the exam's current equipment rules and use a permitted handheld in the room.
Do I need an account or an app download?
No. The calculator is free to use in your browser without an account. Sign in only if you want your calculation history on another device.
Does it show steps or graph functions?
Yes. Tales Math Solver can open from a result for supported step-by-step problems. The Graph tab plots functions and equations and lets you inspect key points on a curve.
About this tool
CalcES is a free online calculator made by MathDa for study and everyday mathematical work. Check critical results independently, especially when a course or professional task calls for a specific method or rounding convention.