Scientific Calculator Online for School, College and Engineering
CalcES is a free online scientific calculator made by MathDa, with keypad layouts modelled on Casio fx-991ES PLUS, fx-82ES PLUS and fx-991CW physical calculators. It runs in your browser on your phone, tablet or PC, with no installation or account needed for calculation and graphing.
Choose the keypad you know
As a scientific calculator simulator, CalcES offers layouts modelled on calculators in the Casio fx-991 family, including the fx-991ES PLUS and fx-991CW. In Settings → Calculator model → Change, select your model code. Models sold in India appear first, then the full list.
If your Casio scientific calculator is an fx-991ES PLUS, practise online with SHIFT, ALPHA, SOLVE, a CALC function and STO/RCL. Use this online calculator when your calci is at home. Advanced keypad is on by default and adds extra functions to keys left blank on the physical calculator. Turning it off shows only printed keys.
CalcES is MathDa's independent product, not affiliated with Casio. Casio, ClassWiz and the model names are trademarks of their respective owners. Firmware, menus and limits differ from physical calculators.
Homework, fractions and trigonometry
Textbook-style input in CalcES displays fractions, mixed numbers, roots, powers and logarithms. Enter 1/2 + 1/3 and keep exact answers as fractions, surds or multiples of π. Use S⇔D for decimals on the fx-991ES PLUS-style keypad, or FORMAT on the fx-991CW-style keypad.
For Class 11 trigonometry, evaluate sin 30° in degrees. Angle settings also cover radians, gradians and degrees, minutes and seconds conversion. You can evaluate log and antilog (10ˣ), inverse and hyperbolic functions. For arithmetic, use recurring decimals, percentages, HCF and LCM or prime factorisation. Factorial, permutations and combinations help count arrangements.
Solve equations and inequalities
In CalcES, enter coefficients to solve simultaneous equations with 2–6 unknowns, such as three circuit equations. Use SHIFT then SOLVE on the fx-991ES PLUS-style keypad or TOOLS → Solve on the fx-991CW-style keypad to solve for x. An expression without '=' is treated as equal to zero. The calculator solves polynomial equations of degrees 2–5, including quadratic and cubic equations, with real or complex roots, and gives a quadratic's vertex. Polynomial inequalities of degrees 2–5 return a solution set. The quadratic equation Guide explains coefficient entry. Ratio finds a missing term in a proportion. Verify reports whether an equality or inequality is true or false.
Engineering: matrices, vectors and complex numbers
For B.Tech coursework, CalcES works as an engineering calculator with Casio-style keys. Engineering notation (ENG) shows 0.0047 A as 4.7×10⁻³ A. Fix/Sci/Norm formats control how results are displayed. Lab work can draw on 47 scientific constants and 40 unit conversions.
In Class 12 maths, find a 3×3 determinant. Matrix templates accept sizes up to 7×7 for inverses, transposes, rank, row reduction and eigenvalues. Use complex numbers in rectangular or polar form for circuits, with modulus, argument and conjugate. With 2-D and 3-D vectors, find magnitudes, angles, unit vectors, the scalar product (dot product) and vector product (cross product).
Differentiation and integration
CalcES evaluates a derivative at a point and a definite integral. For x², find the derivative at x = 3 or integrate from 0 to 1. You can also evaluate left-hand and right-hand (one-sided) limits, two-sided limits, sums and products of sequences.
Statistics and probability
In Statistics, CalcES calculates mean, variance, standard deviation and quartiles from a frequency table for B.Com, economics and B.Sc coursework. A frequency column supports up to 999 data rows, and seven regression models fit paired lab readings.
The Distribution mode calculates binomial, normal and Poisson probabilities, cumulative probabilities and inverse normal. Teachers can demonstrate relative frequency with Math Box dice rolls and coin tosses.
Reuse formulas, tables and spreadsheets
CALC reuses formulas in CalcES, such as x² + y² with new x and y values. Use STO/RCL to store and recall values. The Variables panel displays and edits ten letter variables plus Ans and PreAns.
You can define f(x) and g(x) once for reuse. The table of values uses a start, end and step, with optional g(x). The Guide explains how to make a table of values. The spreadsheet supports columns A–Z and 999 rows, cell formulas, relative and absolute references, and Sum, Mean, Min and Max over ranges. Fill, copy and paste repeat formulas across cells.
Chemistry and computer-science calculations
In CalcES, the periodic table lists 118 elements with atomic weights. Enter NaCl to find its molar mass.
Base-N shows decimal, binary, octal and hexadecimal together. Use it for decimal-to-binary base conversion or AND, OR and XOR bitwise operations on signed 32-bit integers.
What a browser adds
Compared with a physical calculator, CalcES adds a live result preview as you type on your phone and computer, before you press =. You can reopen, edit and re-run the latest 100 calculations and sync calculation history across devices after sign-in.
Turn on Indian Style Digit Grouping in Settings to read results in lakhs and crores without changing the value.
Tales Math Solver, the built-in step-by-step solver, opens from an expression or result. It offers a few free trial solves for supported problems before sign-in.
Scan a printed sum with your phone camera, upload or paste an image, or draw a handwritten expression. Check the editable input before calculating, especially minus signs and fractions. The Graph tab and graphing calculator plot functions, curves and inequality regions for Class 12 linear programming. A result's Graph button sends supported functions, tables and calculus results to the graph.
Calculator skins and light and dark themes customise the display. Key sounds are optional. Vibration works on supported phones. Guide articles explain your model's keys.
Frequently asked questions
Is there a free online calculator for fx-991ES PLUS or fx-991CW users?
Yes. CalcES is a free online scientific calculator with keypads modelled on Casio fx-991ES PLUS, fx-82ES PLUS and ClassWiz fx-991CW for your phone or computer. It is not affiliated with Casio.
Do I need to install a calculator app on my PC or sign in?
No. CalcES runs in your browser without installing an emulator or a calculator app. On a PC, type with your keyboard, use keyboard shortcuts and work on a larger screen. You can add it to your phone's home screen as a web app. Calculation and graphing need no account. Tales Math Solver offers a few free trial solves before sign-in.
Is there a free engineering calculator online for B.Tech?
Yes. CalcES works as a free online engineering calculator for B.Tech coursework, with ENG notation, complex numbers for circuits and matrices up to 7×7 for linear algebra. You can use 47 scientific constants and 40 unit conversions for lab calculations.
Is there a scientific calculator online with SHIFT SOLVE?
Yes. In CalcES, press SHIFT then SOLVE on the fx-991ES PLUS-style keypad, or open TOOLS → Solve on the fx-991CW-style keypad, to solve an equation for its unknown. An expression without '=' is treated as equal to zero.
Which keypad should I choose for a Casio fx-991CW (ClassWiz CW)?
Choose the fx-991CW-style keypad in CalcES if you own a Casio fx-991CW. It uses CW keys and menus, including TOOLS and FORMAT. Open Settings → Calculator model → Change and select your model code, like fx-991CW.
Can I solve three simultaneous equations and see the steps?
Yes. CalcES solves linear simultaneous equations with 2–6 unknowns from coefficients. Tales Math Solver, CalcES's step-by-step solver, shows worked steps for supported problems. Some results have no worked explanation.
How do I find standard deviation from a frequency table?
Use the frequency column in CalcES Statistics to enter each value and its frequency. The table gives standard deviation, mean, variance and quartiles.
Can I find a large matrix's inverse and determinant online?
Yes. CalcES accepts matrices up to 7×7 and calculates determinants and inverses.
Can I calculate molar mass from a chemical formula?
Yes. CalcES calculates molar mass from formulas using its periodic table of 118 elements.
Can I take a photo or enter a handwritten expression?
Yes. CalcES accepts photos, uploaded or pasted images and handwritten expressions. Check the editable input before calculating.
Can I use CalcES in a JEE, GATE or college exam room?
No. CalcES is a website for study and practice, not exam-room use. Follow your examination or institution's current equipment rules.
About CalcES
MathDa makes CalcES for learning maths and technical calculations. Check important results and rounding against your course materials.