Free online statistics calculator: compute mean, median, standard deviation, linear regression, t‑tests, chi‑square, and probability distributions. Runs in any browser. AP Statistics‑ready. No sign-up needed.
Statistics tool loading…
This is a free browser-based statistics calculator that follows the TI-84 Plus CE STAT menu workflow — 1-Var Stats, regression, hypothesis tests, and probability distributions. If you are taking AP Statistics, college intro stats, or any course that involves data analysis, this calculator does everything a TI-84 does but is free and runs 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, pasting CSV or tab-separated values, or uploading a file — up to 10,000 data points per list. Results recalculate 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 t-test or regression in about one minute:
Choosing the right test is half the battle in statistics. Here is a quick guide:
| What you want to know | Test to use | What the output tells you |
|---|---|---|
| Is there a difference between two group means? | Two-sample t-test | t-statistic and p-value — if p < 0.05, the difference is likely real |
| Does a sample mean differ from a known value? | One-sample t-test | Whether your sample could have come from a population with that mean |
| Are two categorical variables related? | Chi-square test for independence | Whether the observed frequencies differ from what chance would predict |
| Do observed frequencies match expected ones? | Chi-square goodness-of-fit | Whether a die is fair, or whether survey results match population proportions |
| 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 test to use, start with the question: "What kind of data do I have?" If you are comparing two means → t-test. If you are checking a relationship between categories → chi-square. If you are modeling a trend → regression. For a deeper walkthrough of when to apply each procedure, 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 ≈ 6.64, population σ ≈ 6.20, Q1 = 80.5, median = 86.5, Q3 = 91. These follow the same STAT menu calculations as a TI-84 Plus CE.
Step 3 — One-sample t-test: The teacher wants to know if the class average is significantly different from 80. Select One-Sample T-Test, enter μ₀ = 80, and use the summary stats from Step 2 (x̄ = 85.875, s = 6.64, n = 8). The output shows t ≈ 2.50, p ≈ 0.041. Since p < 0.05, reject H₀ — the class mean is significantly higher than 80.
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. Enter your dataset and the calculator returns the mean, variance, standard deviation, and z‑scores for every data point. Population standard deviation (σ) and sample standard deviation (s) are shown as separate clearly labeled results. This is the distinction AP Stats teachers emphasize most — and the calculator makes it obvious which one you are looking at.
Yes. Every calculation displays both population (σ, σ²) and sample (s, s²) results. The calculator defaults to sample statistics, but you can switch to population mode in the settings. Using the wrong standard deviation will throw off your confidence intervals and hypothesis tests — showing both prevents this mistake.
Yes. The calculator runs one‑sample, two‑sample, and paired t‑tests, plus chi‑square goodness‑of‑fit and test for independence. Every test returns the test statistic, p‑value, and confidence interval, with a clear conclusion at common alpha levels (0.05 and 0.01). The output follows TI‑84 Plus CE conventions.
Yes. Paste comma‑separated or tab‑separated values into the list editor, type numbers directly into the six list columns (L₁ through L₆), or drag‑and‑drop a CSV file. The calculator handles up to 10,000 data points per list. Each list auto‑saves in your browser, so your data survives a page refresh.
Yes. The calculator covers exploratory data analysis (five-number summaries, box plots, histograms), regression (linear and nonlinear with residual plots), probability distributions, confidence intervals, and hypothesis tests (t-tests, z-tests, chi-square). It mirrors the STAT menu 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. You can also export your data as a CSV file or paste it into a spreadsheet. If you clear your browser data, the saved lists will be reset.
The calculator supports a wide range of regression models: linear, quadratic, cubic, quartic, logarithmic, exponential, power, logistic, and sinusoidal, among others. Each model returns coefficients (a, b, c, etc.), r (correlation), r² (coefficient of determination), and residual plots. 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: August 4, 2026
TI-84 Plus CE is a trademark of Texas Instruments Incorporated. Calc84 is an independent educational project by Miqdad Qaisrani, not affiliated with or endorsed by Texas Instruments. Full disclaimer.
© 2025-2026 Miqdad Qaisrani. All Rights Reserved.