Free Online Scientific Calculator
A truly full scientific calculator online, free: definite integration, differentiation, summation, matrices, vectors, complex numbers, statistics with regression, quadratic / cubic / simultaneous equation solving, and base-N binary, octal and hexadecimal arithmetic — 403 functions across 10 modes, exactly like the Casio fx-991ES PLUS.
Runs in your browser with a natural textbook display — no download, no sign-up, and it works offline as a PWA.
What Makes a Calculator Truly Scientific?
Search "scientific calculator" and most results are really basic calculators with trig and log keys bolted on. A genuine scientific calculator goes much further — here's the difference.
| Capability | Basic "scientific" calculators | This calculator |
|---|---|---|
| Trigonometry, logarithms, powers & roots | Yes | Yes |
| Fractions & natural textbook display | No | Yes |
| Definite integration & differentiation | No | Yes |
| Summation (Σ) of series | No | Yes |
| Matrices & vectors | No | Yes |
| Complex numbers (a+bi, polar) | No | Yes |
| Equation solver (quadratic, cubic, simultaneous) | No | Yes |
| Statistics & 7 regression types | No | Yes |
| Base-N (binary / octal / hex) & bitwise | No | Yes |
A Complete Scientific Calculator
Every function you need, in one free online tool
Integration Calculator
Compute definite integrals numerically. Enter ∫(f(x), a, b) — supports polynomial, trigonometric, exponential, and logarithmic integrands.
Derivative Calculator
Numerical differentiation at any point. Use d/dx(f(x), a) to find the derivative of any expression instantly.
Summation Calculator
Evaluate finite sums with Σ(f(x), start, end). Useful for series, sequences, and discrete mathematics.
Matrix Calculator
Add, subtract, multiply matrices up to 3×3. Compute determinant, inverse, and transpose with a few button presses.
Complex Number Calculator
Arithmetic in rectangular a+bi and polar r∠θ form. Includes modulus, argument, and conjugate.
Equation Solver
Solve quadratic, cubic, and simultaneous linear equations (2–3 unknowns). Get all real and complex roots instantly.
Binary & Hex Calculator
Convert between binary, octal, decimal, and hexadecimal. Bitwise AND, OR, XOR, XNOR, NOT supported.
Statistics Calculator
Mean, standard deviation, variance, and 7 regression types: linear, quadratic, logarithmic, exponential, power, and inverse.
Fraction Calculator
Enter and simplify fractions and mixed numbers. Toggle between exact fraction and decimal display with S⇔D.
How to Use This Online Scientific Calculator
No account and no manual required — but if you want the full walkthrough, here's how the six steps work.
- 1
Pick a mode.
Press MODE and choose COMP for everyday calculations, or CMPLX, STAT, BASE-N, EQN, MATRIX, VECTOR, or TABLE for specialized math.
- 2
Enter your expression.
Click the on-screen keys or type on your keyboard — the natural display renders fractions, powers, and roots exactly like the physical Casio fx-991ES PLUS.
- 3
Unlock extra functions with SHIFT and ALPHA.
SHIFT gives you each key's yellow function (like ∫dx or x!); ALPHA gives you the red variable/letter functions.
- 4
Press = to evaluate.
Trailing brackets close automatically, so cos(45 evaluates the same as cos(45).
- 5
Toggle exact vs. decimal form.
Use the FRAC pill or the S⇔D key to switch a result between fractions/surds and decimals.
- 6
Reuse work with memory and history.
STO/RCL save values to variables A–F, X, Y; the history panel keeps every past calculation one tap away.
Frequently Asked Questions
Is this online scientific calculator free?+
Yes. It runs entirely in your browser at no cost, with no sign-up required, and works offline once loaded as a PWA.
What makes a calculator truly scientific?+
Beyond trig, logs and roots, a genuine scientific calculator supports calculus (integration and differentiation), matrices, complex numbers, statistics with regression, equation solving, and base-N arithmetic — all of which this calculator includes.
How is this different from Desmos or Google's calculator?+
Most "scientific" calculators online only cover trigonometry, logarithms and roots. This one adds definite integration, differentiation, summation, matrices, vectors, complex numbers, statistics with 7 regression types, an equation solver, and base-N arithmetic — 403 functions across 10 modes.
How do I compute a definite integral online?+
Switch to COMP mode and enter ∫(f(x), a, b), where a and b are the lower and upper bounds — the result is computed numerically.
Can I use this as a derivative calculator?+
Yes — use d/dx(f(x), a) to get the numerical derivative of f(x) at the point a.
How do I solve a quadratic equation?+
Switch to EQN mode, choose the quadratic (or cubic, or simultaneous) equation type, enter the coefficients, and the calculator returns all real and complex roots.
How do I convert decimal to binary or hexadecimal?+
Switch to BASE-N mode. You can enter a value in any base and convert it to binary, octal, decimal or hexadecimal, plus run bitwise AND, OR, XOR, XNOR and NOT operations.
Does this calculator support complex numbers?+
Yes — CMPLX mode supports arithmetic in rectangular (a+bi) and polar (r∠θ) form, including modulus, argument, and conjugate.
Can I do matrix calculations online?+
Yes — MATRIX mode supports addition, subtraction, and multiplication of matrices up to 3×3, plus determinant, inverse, and transpose.
Does it work on mobile phones and tablets?+
Yes, the layout is responsive and touch-friendly, and it can be installed as a PWA for an app-like offline experience.
What is the Casio fx-991ES PLUS?+
It's one of the most widely used physical scientific calculators for students and engineers. This tool mirrors its 403 functions and natural textbook (Natural-V.P.A.M.) display in the browser.
How do I use keyboard shortcuts?+
You can type expressions directly on your keyboard in addition to clicking the on-screen keys — the natural display updates as you type.
Try the Full Scientific Calculator
Free online scientific calculator — a truly full-function Casio fx-991ES PLUS. Integration · Derivative · Matrix · Statistics · Complex Numbers · Equation Solver · Binary & Hex.
Visit calculator.appynox.com