Quick guide
- Use the simulator to build intuition and compare theory vs runs.
- Use the tree / 2×2 table to structure AND/OR/NOT.
- Use nCr/nPr for combinations and permutations.
Tools
- Distribution sampler – random samples & histograms (normal, Poisson) | CalcBE
Generate random samples from common distributions (normal, log-normal, gamma, poisson, and more). Visualize histograms, check summary stats, and download CSV/JSON — runs locally in your browser.
- Randomness tests – chi-square, runs, ACF, JB | CalcBE
Run chi-square, runs, autocorrelation, and Jarque–Bera on bit or number sequences. Visualize results and download a report—runs locally in your browser.
- Shuffle bias comparison – naive vs Fisher–Yates | CalcBE
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- Stochastic process visualizer – random walk & Markov chain | CalcBE
Visualize random walks (1D/2D) and Markov chains from a transition matrix. See trajectories, MSD, and stationary distribution, then download results.
- Dice stats (odds & distribution) + PNG sharing | CalcBE
Compute odds and distributions for NdS +/- K. Auto switches Exact/Sim, shows a histogram, and lets you share as text, PNG, or URL — in your browser.
- Dice roller (d4–d100) with PNG sharing | CalcBE
Roll d4–d100 with quick buttons or 2d6+3 notation. See totals and breakdowns, save history, and share as text or PNG — all in your browser.
- TRPG dice check (d20/d100, pools) with PNG sharing | CalcBE
Run d20/d100 checks with advantage/disadvantage, compare vs DC, and roll dice pools to count successes. Share as text, PNG, or URL — all in your browser.
- Random Number Generator | Integers, decimals, seeds
Generate random integers or decimals in your browser with optional seeds, unique values, and copyable results. Everything runs locally without sending data to the server.
Calculators
- Probability Simulator — coin, dice, roulette (theory vs empirical, with steps) | CalcBE
Simulate coin tosses, dice rolls and roulette spins with a fixed seed to compare theoretical and empirical probabilities. Inspect confidence intervals, convergence charts and shareable runs.
- Probability tree & 2×2 table — AND/OR & complement | CalcBE
Probability tree & 2×2 table tool for AND/OR/NOT and complements. Highlights matching paths/cells and explains products, sums, and 1−P with steps. Copy a shareable URL, SVG, or LaTeX.
- Birthday paradox (collision probability) calculator | CalcBE
Calculate the birthday paradox collision probability with exact math + a Monte Carlo simulator. Get P(collision), P(no collision), a Poisson approximation with error, and the required sample size n for a target probab…
- Coupon collector calculator (expected draws) | CalcBE
Solve the coupon collector problem: expected draws, t50/t90/t99, P(T≤t), weighted rarities, and a reproducible Monte Carlo simulation.
- Distribution calculator – binomial, Poisson, t, chi-square | CalcBE
Compute PMF/PDF, CDF, quantiles, and exact confidence intervals for binomial, Poisson, Student's t, and chi-square distributions with step-by-step explanations, graphs, CSV, LaTeX, and shareable URLs.
- Hypergeometric calculator (without replacement) | CalcBE
Compute hypergeometric probabilities (without replacement): P(X=k), tails, and ranges. PMF chart/table, seeded simulation, share URL, and CSV.
- nCr & nPr calculator (permutations & combinations) | CalcBE
Compute nCr (combinations), nPr (permutations), and factorial (n!). Exact BigInt results, step logs, teacher mode, and shareable links.