Free scientific calculator engine
A full math engine for arithmetic, parentheses, powers, roots, logarithms, constants, percentages and scientific notation — free, with no download.
Free Fx-991ES Casio-style scientific calculator
Casio Scientific
Calculator Online 991ES & 991EX
A free online scientific calculator with a 991ES Casio-style layout — trigonometry, logarithms, powers, roots, fractions and scientific notation, ready in your browser with no download.
9Languages
6Color themes
100%Free forever
Casio FX-991ES Scientific Calculator View
Casio Scientific Calculator
8 MODES · EXACT RESULTS
SETUP
SOLVE =
d/dx :
x!
Σ(
a b/c
∛□
x³ DEC
■√□ HEX
10■ BIN
e■ OCT
∠ A
← B
Abs C
sin⁻¹ D
cos⁻¹ E
tan⁻¹ F
STO
← i
%
, X
a b/c⇔d/c Y
M- M
CONST
CONV
CLR
INS
OFF
MATRIX
VECTOR
FACT
nPr
nCr
STAT
CMPLX
BASE
Pol
Rec
Rnd Ran#
RanInt#
π e
DRG
≈
CALCULATION HISTORY
No history yet
Features
Core Casio scientific calculator functions
Trigonometry calculator modes
Switch between DEG and RAD for sine, cosine, tangent and inverse trig functions, just like a physical Casio.
Online calculator with history & keyboard
Reuse your last answer with Ans and type expressions straight from a desktop keyboard into this online scientific calculator.
Calculation modes
8 scientific calculator modes in one free online tool
COMP — standard scientific calculator
The default mode for everyday arithmetic with exact fractions — 1/3 stays 1/3, never 0.3333.
STAT — statistics calculator
Mean, standard deviation and data analysis with no extra app — press SHIFT + 1.
MATRIX & VECTOR — matrix calculator
Matrix entry, row operations and vector calculations for linear algebra — SHIFT + 4 for matrices, SHIFT + 5 for vectors.
CMPLX — complex numbers
Complex number (a+bi) operations for electrical engineering and advanced math — press SHIFT + 2.
BASE-N — number base conversion
Binary, octal, decimal and hexadecimal conversion for computing and digital systems courses.
TABLE — function table generator
Auto-generate f(x) value tables to plot graphs and check function patterns.
Every mode follows the Casio fx-991ES Plus key layout — the key sequences you memorized on the physical calculator work here too.
How to use
Enter, calculate, reuse results
1
Enter an expression
Tap the keys or use your keyboard to type numbers, operators and functions.
2
Choose DEG or RAD
Set the angle mode before calculating any trigonometric expression.
3
Press equals
See the result instantly, then reuse it with Ans in your next calculation.
Not sure what a key does? The complete button manual explains SHIFT, ALPHA and MODE step by step.
Online scientific calculator
A fast Casio-style scientific calculator for everyday math
Built for practical calculations
This free Advanced scientific calculator online gives students, teachers and engineers a familiar Casio calculator online layout — no account or install needed.
Useful for school and engineering work
Use this casio scientific calculator online for trigonometry, logarithms, physics formulas and everyday arithmetic, with DEG/RAD to match your textbook.
Mobile-friendly scientific calculator
Large touch keys work well on phones and tablets, while full keyboard support keeps desktop use fast.
Need formulas beyond percentages? Browse all math formulas from A to Z.
Model & function guide
Popular scientific calculator casio searches
Casio fx-991EX scientific calculator online
A popular model among students — practice the same functions here in a browser-based scientific calculator.
Casio fx-991ES Plus online
Use an online scientific calculator for fractions, trigonometry, powers, roots and logarithms.
Casio fx-570MS and fx-570ES
Looking for an fx-570MS or fx-570ES online? Use this browser calculator for the same core operations.
Scientific calculator with fractions
Work with fractional values for algebra, geometry and physics, and check them against decimal results.
SHIFT and advanced functions
A familiar SHIFT control reaches extra operations alongside trig, log and root functions.
Scientific calculator emulator & app alternative
A calculator casio online free alternative to installing an app — works on desktop and mobile browsers.
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Still have a question? Find quick answers in the frequently asked questions.
FAQ
Common questions
Is this an official Casio calculator?
No. This is an independent casio calculator online free tool with a Casio-style layout. Casio and its model names belong to their owner.
Is this calculator free?
Yes — this casio online calculator free tool works directly in your browser at no cost.
Does it work on mobile?
Yes. The layout is responsive across phones, tablets and desktop browsers.
Does it support fractions?
It's built around scientific calculation workflows, including fraction-related work.
What is DEG/RAD mode?
DEG reads angles in degrees; RAD reads them in radians — match the mode to your formula.
Can I use it for school or exams?
Use it for practice and everyday calculation, but always follow your school's or exam board's calculator rules.
What calculation modes does this scientific calculator have?
Eight modes: COMP (standard), STAT (statistics calculator), MATRIX & VECTOR (matrix calculator), CMPLX (complex numbers), BASE-N (base conversion) and TABLE (function table) — just like a real Casio fx-991ES Plus.
Can it calculate matrices and statistics?
Yes. Press SHIFT + 4 for matrix mode, SHIFT + 5 for vectors and SHIFT + 1 for statistics (mean, standard deviation). Everything runs free in your browser.