Is this graphing calculator really free?

Yes, completely free with no sign-up, no downloads, and no hidden fees. It's ad-supported so it can remain free for everyone.

Can this replace a TI-84 calculator?

Yes. This tool provides the same core functionality as a TI-84 — graphing functions, statistical analysis (LinReg, QuadReg), matrix operations (RREF, inverse, determinant), and distribution functions (normalcdf, invNorm, tcdf, binompdf) — with a modern, HD interface.

What types of functions can I graph?

You can graph standard functions (polynomial, trigonometric, logarithmic, exponential), parametric equations (X(t)/Y(t) pairs), and polar functions (r = f(θ)). Plot up to 10 functions simultaneously with individual color coding.

How do I perform a linear regression?

Switch to Stat mode, enter your data into lists L1 and L2, then select LinReg from the regression menu. You'll get the slope (a), intercept (b), correlation coefficient (r), and R² value — just like the TI-84 STAT > CALC > LinReg(ax+b) workflow.

Does it support normalcdf and invNorm like a TI-84?

Yes. The Distribution mode includes normalcdf, invNorm, normalpdf, tcdf, invT, chi-square CDF, binomial PDF/CDF, and Poisson PDF/CDF — all matching TI-84 output to 4 decimal places.

Can I do matrix operations like RREF?

Yes. The Matrix mode supports addition, multiplication, scalar multiplication, transpose, determinant, inverse, and RREF (Reduced Row Echelon Form) for up to 10 named matrices [A] through [J].

Does it support degree and radian mode?

Yes. Toggle between degree and radian mode for all trigonometric calculations, just like the MODE button on a TI-84. The current angle mode is always visible in the toolbar.

Is this tool accurate for homework and exams?

Yes. All calculations are verified against TI-84 reference outputs and published statistical tables with over 200 automated tests ensuring accuracy to at least 4 decimal places.

Free Graphing Calculator

A powerful graphing calculator with TI-84 style statistics, matrices, and distributions — a free alternative to TI-84 online emulators. No sign-up required.

Plot up to ten functions, run linear and quadratic regressions, solve matrices, evaluate distributions, and step through tables — with a TI-84 keypad workflow rendered in HD. Supports angle modes, scientific notation, and store-to-variable (sto→). No download, no calculator price tag, no proctored-exam mode. A free alternative to the TI-84 Plus CE and Desmos for homework, quick checks, and classroom demos.

Built and maintained by James Nicolaus

HD Function Graphing

Plot up to 10 functions simultaneously — standard, parametric, and polar. Pan, zoom, and trace with a modern canvas renderer that makes TI-84's 96×64 pixel screen look ancient.

Statistics & Regression

Enter data into lists L1–L6, compute 1-Var Stats, and run LinReg, QuadReg, ExpReg, and PwrReg — with correlation coefficients and scatter plots.

Matrix Operations

Work with up to 10 matrices [A]–[J]. Add, multiply, find determinants, compute inverses, and row-reduce to RREF — all with a proper grid editor.

Distribution Functions

normalcdf, invNorm, tcdf, binompdf, chi-square, and Poisson — the same distribution functions from the TI-84 DISTR menu, with shaded area visualizations.

Free Online Graphing Calculator — TI-84 Alternative

Free Tool Shed's graphing calculator brings TI-84 functionality to your browser with a modern, high-definition interface. Plot functions in crisp detail instead of on a 96×64 pixel screen. Run linear regressions, compute matrix operations, and evaluate distribution functions — all without buying a $100+ calculator or downloading a sketchy ROM emulator. Every calculation is verified against TI-84 reference outputs with over 200 automated tests, so you can trust the results for homework, exams, and research.

Need to convert units inside your problem set? The free unit converter covers 800+ units across 23 categories. Working on a chemistry assignment? The free interactive periodic table handles molar mass, electron configurations, and trend heatmaps.

Features

Plot up to 10 functions simultaneously with individual colors
Standard, parametric (X(t)/Y(t)), and polar (r=f(θ)) graphing modes
Interactive pan, zoom, and trace with coordinate readout
Auto-generated x/y value tables with configurable step size
Degree and radian mode toggle for all trig functions
1-Var Stats: mean, median, standard deviation, five-number summary
Regression: LinReg, QuadReg, ExpReg, PwrReg with r and R² values
Data entry in lists L1–L6 with scatter plot overlay
Matrix operations: add, multiply, determinant, inverse, RREF, transpose
Up to 10 named matrices [A]–[J] with resizable grid editor
Normal distribution: normalcdf, invNorm, normalpdf
t-distribution: tcdf, invT — with shaded area visualization
Binomial: binompdf, binomcdf — matching TI-84 DISTR menu
Chi-square and Poisson distribution functions
Command palette (Ctrl+K) for quick function access
localStorage persistence — your work survives page reload

How to Use the Graphing Calculator

Graph a function: In Graph mode, type an expression like sin(x) or x^2 - 4 into a Y= slot and see it plotted instantly.
Run a regression: Switch to Stat mode, enter x-values in L1 and y-values in L2, then choose LinReg, QuadReg, ExpReg, or PwrReg from the regression menu.
Solve a system with RREF: In Matrix mode, enter the augmented matrix and click RREF. The reduced row echelon form gives you the solution directly.
Compute a normal probability: In Dist mode, select normalcdf, enter lower bound, upper bound, mean, and standard deviation — just like the TI-84 DISTR menu.
Generate a table: Switch to Table mode, set your start value and step size, and view computed y-values for all active functions.

Comparison: Free Tool Shed vs. TI-84 vs. Desmos

Feature	Free Tool Shed	TI-84	Desmos
Price	Free	$100+	Free
Graph resolution	HD canvas	96×64 px	HD canvas
Function graphing	✓	✓	✓
Parametric/Polar	✓	✓	✓
Statistics (1-Var)	✓	✓	Limited
LinReg/QuadReg	✓	✓	✗
Matrix RREF	✓	✓	✗
normalcdf/invNorm	✓	✓	✗
Binomial/Poisson	✓	✓	✗
TI-84 menu structure	Familiar	Native	Different
Works in browser	✓	Emulators only	✓
No sign-up required	✓	N/A	✓ (basic)

Tips, Mistakes & Takeaways

Tips

→Use sto→ to save a value to a variable (A–Z or Theta) — then reuse it across functions without retyping.
→Switch the angle mode (Degree vs Radian) before evaluating trig — the same expression returns different values in each mode.
→Set the viewing window manually with WINDOW when ZoomFit picks something unhelpful.
→Run regressions from the stat editor — enter your data points first, then call LinReg, QuadReg, or ExpReg from the calc menu.
→Use the TABLE view to scan many function values quickly instead of evaluating them one at a time.

Common Mistakes

!Plotting a rapidly oscillating function at the default window — you'll see a fuzzy band, not the curve. Zoom in to expose the wave.
!Forgetting the angle mode is global — flipping from Radian to Degree mid-session changes results everywhere.
!Comparing floats with == (sin(π) == 0 almost never is) — check |value| < ε instead.
!Expecting CAS — this is a numeric calculator like the TI-84, not Wolfram Alpha or a TI-Nspire CAS.

Key Takeaways

✓Numeric graphing, statistics, matrices, and distributions — TI-84 workflow, HD interface.
✓Calculator state is in-memory — refreshing the page resets variables and the graph window.
✓Not a CAS — no symbolic differentiation, integration, or simplification.

Frequently Asked Questions

Is this accurate enough for my statistics class?

Yes. All calculations are verified against TI-84 reference outputs with over 200 automated tests. Results match to at least 4 decimal places — the same precision your TI-84 displays.

Can I use this on an exam?

That depends on your instructor's policy. Many allow browser-based calculators for online exams. This tool runs entirely in your browser with no server communication, so it works offline after the initial load.

Why not just use Desmos?

Desmos is excellent for graphing but doesn't include statistics (regression, distributions) or matrix operations. If your textbook references TI-84 workflows (STAT > CALC > LinReg, DISTR > normalcdf), this tool follows those same workflows with a modern UI.

Does it save my work?

Yes. Your functions, data lists, matrices, and settings are automatically saved to your browser's localStorage and restored when you return.

What functions does the expression parser support?

Standard arithmetic (+, -, *, /, ^), trig (sin, cos, tan, asin, acos, atan), logarithms (log, ln, log10, log2), exponentials (exp, e^x), roots (sqrt, cbrt), and more. Constants pi and e are built in.