Free online statistics calculator: compute mean, median, standard deviation, 1‑Var and 2‑Var stats, nine regression models, and probability distributions (normal, t, chi-square, binomial, Poisson). Runs in any browser. No sign-up needed.
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This is a free browser-based statistics calculator that follows the TI-84 Plus CE STAT menu workflow — 1-Var Stats, 2-Var Stats, nine regression models, and probability distributions. If you are taking AP Statistics, college intro stats, or any course that involves data analysis, this calculator covers the core STAT menu calculations, free and running in your browser. Enter your numbers into a list, pick an analysis, and get results instantly. The calculator shows both population (σ) and sample (s) standard deviation side by side for every 1-Var Stats calculation, so you never mix them up on a test. This distinction is one AP Stats teachers emphasize constantly, and this tool makes it impossible to miss.
You can enter data by typing directly into the grid, or by copying a column of values from a spreadsheet and pasting it into a cell — up to 50 values per list. The plot redraws the moment your data lands. Regression models follow the same conventions as a physical TI-84 Plus CE. If you are working through a linear regression problem, the calculator returns a, b, r, and r² — the same values you would see on the handheld.
Here is how to go from a blank list to a completed 1-Var Stats summary or regression in about one minute:
Choosing the right function is half the battle in statistics. Here is a quick guide:
| What you want to know | Function to use | What the output tells you |
|---|---|---|
| How do I summarise one list of numbers? | 1-Var Stats | Mean, sample and population standard deviation, and the five-number summary |
| How do I compare two paired lists? | 2-Var Stats | Means, sums, and sample standard deviations for both lists side by side |
| How likely is a value this far from the mean? | normalCdf( or tCdf( | The area between two bounds under the distribution you choose |
| What is the cut-off for a given tail area? | invNorm(, invT(, or invχ²( | The x-value that corresponds to the area you specify |
| What is the probability of exactly k successes? | Binomial PDF | P(X = k) for n trials with probability p |
| What is the probability of at most k successes? | Binomial CDF | P(X ≤ k) — useful for "at most" or "no more than" questions |
If you are not sure which function to use, start with the question: "What kind of data do I have?" If you are summarising one list → 1-Var Stats. If you are looking at how two lists move together → 2-Var Stats or a regression. If you are modelling a trend → choose a model from the Regression tab, or let Best Fit Model run all nine and report the highest r². For a deeper walkthrough of the regression workflow, the TI-84 linear regression guide goes through a full AP Stats problem from data entry to conclusion.
Here is a realistic AP Statistics problem you can follow along with:
The data: A teacher records test scores for 8 students: 78, 85, 92, 88, 76, 95, 83, 90.
Step 1 — Enter the data: Paste these numbers into L₁: 78, 85, 92, 88, 76, 95, 83, 90.
Step 2 — Run 1-Var Stats: Click 1-Var Stats on L₁. The output shows: mean = 85.875, sample standard deviation s ≈ 6.66, population σ ≈ 6.23, Q1 = 80.5, median = 86.5, Q3 = 91. These follow the same STAT menu calculations as a TI-84 Plus CE.
Step 3 — Find a percentile: Suppose the teacher wants the cut-off score for the top 10% of a normal distribution. Open the Distr tab and run invNorm( with area 0.90 and the mean and standard deviation from Step 2. The calculator returns the x-value that leaves 10% of the area above it. If you already have two bounds and want the area between them instead, use normalCdf(.
This is exactly the kind of question that appears on the AP Statistics exam. Our TI-84 graphing calculator guide covers the STAT menu in detail for students who want the full handheld workflow.
Yes. Run 1‑Var Stats on a list and the calculator returns the mean, sample standard deviation (Sx), population standard deviation (σx), and the five‑number summary. The variance( button returns the sample variance for the same list. Population and sample results are shown as separate clearly labelled rows, so the distinction AP Stats teachers emphasize most is always visible on screen.
Both are reported together rather than behind a mode switch. A 1‑Var Stats run returns Sx (sample) and σx (population) as separate labelled rows, so you read the row you need instead of setting a mode and hoping it was the right one.
Not as one‑click wizards. There is no screen that takes your raw data and hands back a t‑statistic or a χ² test statistic. What the calculator does provide is the distribution machinery those procedures are built on: tPdf(, tCdf(, and invT( for the t distribution, and χ²pdf(, χ²cdf(, and invχ²( for the chi‑square distribution, each with an adjustable degrees‑of‑freedom parameter. You work out your own test statistic, then use these functions to get the p‑value or the critical value.
Yes. Type numbers straight into the six list columns (L₁ through L₆), or copy a column from a spreadsheet and paste it into a cell — the paste splits on commas and line breaks and fills downward. There is no file upload. Each list holds up to 50 values and auto‑saves in your browser, so your data survives a page refresh.
It covers the descriptive and modelling side of the course: exploratory data analysis (five‑number summaries, box plots, histograms, scatter plots), nine regression models, and the probability distributions used throughout the curriculum (normal, t, chi‑square, binomial, Poisson). The inference procedures themselves are not run as one‑click routines, but the distribution functions you need to carry them out are all here. The layout mirrors the STAT and DISTR menus on the TI‑84 Plus CE, which is the calculator most AP Stats students use.
Use population standard deviation (σ) when your data includes every member of the group you are studying — like test scores for every student in one class. Use sample standard deviation (s) when your data is a subset — like a random sample of 100 voters. When in doubt, use sample (s). The calculator shows both for every 1-Var Stats calculation so you can compare. This distinction matters a lot for confidence intervals and hypothesis testing.
Yes. All list data (L₁ through L₆) auto-saves in your browser's local storage. Close the tab, reopen it, and your numbers are still there. If you clear your browser data, the saved lists will be reset.
The calculator runs nine regression routines: linear (LinReg ax+b and a+bx), quadratic, cubic, quartic, logarithmic, exponential, power, logistic, and sinusoidal. Each returns its coefficients (a, b, c, and so on) and r², with r also reported for the linear, logarithmic, exponential, and power forms. The fitted curve is drawn over your scatter plot, and Best Fit Model runs all nine and reports the highest r². The output follows the TI-84 Plus CE Stat CALC menu. For a step-by-step walkthrough, see our linear regression tutorial.
Going deeper: our linear regression tutorial walks through scatter plots and lines of best fit using STAT PLOTS, while the graphing calculator plots your regression results visually. For the matrix operations behind chi-square problems, the matrix calculator covers that ground. For a refresher on the underlying theory, Khan Academy’s statistics course and the American Statistical Association education page are both solid starting points.
Page last updated: October 13, 2026
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