Start here
Pick one task first: equations, percentages, geometry, or probability.
Open Featured for the most common classroom workflows.
Use Math & statistics when you need the full tool list.
Featured
- 2D graphing calculator – plot and intersect functions
Plot up to three functions, find intercepts, intersections, and extrema, then share the graph URL with step logs.
- Quadratic & Polynomial Solver with Steps
Solve quadratic and degree-3 polynomial equations with exact and decimal roots, discriminant checks, factorization, completing the square, graph view, and step logs.
- Quadratic Equation Solver – Roots, Discriminant & Vertex
Solve ax² + bx + c = 0 and see real or complex roots, the discriminant, vertex form and a quick graph.
- Fraction Simplifier & Mixed Number Converter
Reduce any fraction, convert between improper and mixed numbers, and review Euclidean GCD steps with pie and number line visuals for lessons.
- Percentage Calculator (X% of Y, increase/decrease)
Work out X% of Y, what percent one number is of another, and the new value after a percent increase or decrease.
- Prime Factorization with Steps & Factor Tree
Factor any integer into primes, see every trial division step, compute τ(n), σ(n), φ(n), and draw the factor tree.
Math & statistics
- Pi lab
Explore how pi is approximated with polygons, series, and simulation.
- Pi Approximation Explorer
Compare polygon, Gregory, Nilakantha, and Monte Carlo approximations of pi with charts, errors, examples, and shareable URLs.
- Pi Algorithm Race
Race Gregory, Nilakantha, Machin-like, and Chudnovsky pi algorithms with fixed-time and fixed-digits modes, charts, CSV export, and shareable URLs.
- Pi Digits Generator
Generate the first n digits of pi with a Chudnovsky-based browser tool.
- Pi Digit Lab
Search for a digit sequence, jump to a position, move block by block, and copy a selected range inside the first n digits of pi.
- Probability Simulator — coin, dice, roulette
Simulate coin tosses, dice rolls and roulette spins with a fixed seed to compare theoretical and empirical probabilities.
- 2D geometry calculator – area & perimeter of shapes
Compute area and perimeter for rectangles, circles, triangles, trapezoids, and regular polygons with formulas for homework and design checks.
- 3D Geometry Calculator (Sphere, Cylinder, Cone, Prism)
Compute volume and surface area for spheres, cylinders, cones, rectangular and regular prisms—with example inputs, step-by-step formulas, and a shareable result link.
- A/B Test Significance Calculator
Check A/B test results with conversion rates, lift, z-test p-value, confidence interval, and Bayesian win probability.
- Algebra simplifier with colors for like terms
Expand with distribution, color-match like terms, and simplify step by step.
- Algebra Worksheet Generator
Create printable algebra handouts with answer keys and optional worked steps.
- ANOVA Calculator
Paste grouped raw values to run a one-way ANOVA, inspect the ANOVA table, F statistic, p-value, eta-squared, and a readable grouped summary chart in your browser.
- Arithmetic & Geometric Sequence Calculator
Compute the nth term, partial sum, common difference or ratio, and number of terms for arithmetic and geometric sequences.
- ARR NNT Calculator
Calculate absolute risk reduction, relative risk reduction, and NNT or NNH from control and experimental event rates.
- Aspect Ratio Calculator
Simplify image or video ratios, solve a missing width or height, and preview contain, cover, and crop behavior inside one box.
- Attributable Fraction Exposed Calculator
Estimate attributable fraction among exposed and attributable percent among exposed from group risk, or from direct attributable risk with exposed-group risk.
- Attributable Risk Calculator
Compare exposed and unexposed groups to review attributable risk and attributable fraction together.
- Attributable Risk Percent Calculator
Estimate attributable risk percent from exposed and unexposed risk, or from a direct attributable risk and exposed-group risk.
- Balanced Accuracy Calculator
Calculate balanced accuracy, recall, specificity, precision, prevalence, and accuracy from TP, FP, TN, and FN.
- Base Converter & Bitwise Toolkit (Bin/Oct/Dec/Hex)
Convert between binary, octal, decimal, and hexadecimal, and run AND/OR/XOR/NOT and bit shifts—then copy a shareable result link.
- Bayes Theorem Calculator
Update a prior probability with Bayes' theorem. Use either sensitivity/specificity for a diagnostic result or direct conditional probabilities for a general event.
- Bell numbers table with Stirling relations
Generate a Bell numbers table B(n) and confirm the relation B(n)=ΣS(n,k).
- Beta Distribution Generator & Visualizer
Generate random samples from a Beta distribution and visualize the PDF and histogram.
- Binomial Test Calculator
Enter successes, trials, and a null proportion to read exact binomial-test p-values.
- Birthday Paradox Calculator (Collision Probability)
Calculate the birthday paradox collision probability with exact math + a Monte Carlo simulator.
- Card deck shuffler – shuffle & draw cards
Shuffle a deck of playing cards and draw or deal cards in your browser.
- Catalan number explorer - Dyck paths & trees
Explore Catalan numbers C_n with exact BigInt or modulo tables, then enumerate or uniformly sample Dyck words, Dyck paths, and full binary trees.
- Chi-Square Test Calculator
Run chi-square goodness-of-fit and independence tests from observed counts.
- Circular & necklace permutation calculator
Compute circular permutations (rotation counted as the same) and necklace/bracelet permutations (rotation + reflection counted as the same) from n.
- Cohen's Kappa Calculator
Calculate Cohen's kappa from paired labels or a contingency table.
- Column arithmetic learning hub
Choose the column-arithmetic page for carries, borrowing, whole-number division, or decimal-point moves in the order you want to learn them.
- Complex Number Calculator — a+bi ↔ polar with steps
Convert between a+bi and r∠θ, perform complex addition, subtraction, multiplication, division, powers, and list n-th roots with a live Argand plot and step-by-step breakdown.
- Confidence Interval & Hypothesis Test Wizard
Build confidence intervals and hypothesis tests for means and proportions with t/z workflows, Welch, paired, Wilson, and Newcombe methods.
- Confusion Matrix Calculator
Calculate confusion matrix metrics for binary classification from TP, FP, TN, and FN.
- Conic sections calculator – standard form & focus
Classify a general quadratic, rotate to eliminate xy, complete the square to standard form, and visualize focus, directrix, and asymptotes.
- Coordinate geometry calculator – distance & lines
Compute distance, midpoint, slope, line equations, circles, and intersections with full working shown beside the results and a live coordinate plane diagram.
- Correlation Calculator
Paste XY pairs to calculate Pearson or Spearman correlation, two-sided p-value, squared coefficient, sample count, and a readable scatter plot in your browser.
- Coupon Collector Calculator (Expected Draws & Completion)
Solve the coupon collector problem with expected draws n·H_n, completion probability P(T≤t), and t50/t90/t99.
- Cp Cpk Calculator
Paste measurements or enter mean and SD with LSL/USL to calculate Cp, Cpk, Pp, Ppk, estimated PPM/DPMO and sigma level with a specification histogram.
- Data visualization: quick charts, CSV profiling, regression
Quick charts, CSV column profiling, histograms, box plots, and regression.
- Decimal Long Division
Learn decimal long division by separating the decimal shift, the transformed equation, and the long-division steps.
- Decimal Long Division
Learn decimal long division step by step. Move both decimal points together, make the divisor a whole number, and continue the written division.
- Decimal Long Multiplication
Learn decimal long multiplication by separating the whole-number multiplication from the step where the decimal point is placed back.
- Descriptive Statistics + Box Plot & Histogram
Paste a dataset or upload CSV/TSV to review descriptive statistics, histogram, box plot, outlier counts, trimmed mean, CSV export, LaTeX summary, and documented steps.
- Diagnostic Odds Ratio Calculator
Calculate diagnostic odds ratio from TP, FP, TN, and FN. Review DOR together with LR+, LR-, sensitivity, specificity, and prevalence at one binary threshold.
- Dice stats (odds & distribution) + PNG sharing
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.
- Differentiation Calculator (steps, tangents, numeric)
Compute symbolic and numeric derivatives for single-variable, parametric, implicit, and partial derivatives.
- Dirichlet Distribution Generator & Visualizer
Generate probability vectors from a Dirichlet distribution and visualize marginals and simplex plots.
- Distributions — binomial, Poisson, t, chi square
Compute PMF or PDF, CDF, quantiles, and exact intervals for binomial, Poisson, Student t, and chi-square distributions.
- Effect Size Calculator
Calculate Cohen's d, Hedges' g, or eta-squared from two-group summaries or one-way ANOVA summaries, then read a cautious magnitude guide beside the value.
- Eigenvalues & Eigenvectors (2x2, 3x3) — with steps
Compute eigenvalues, eigenvectors, multiplicities, residuals, and steps for 2x2 and 3x3 matrices.
- Entropy and KL Divergence Calculator
Calculate entropy, cross-entropy, KL divergence, and JS divergence from probability vectors P and Q.
- Error Propagation Calculator with Steps
Propagate uncertainty for sums, products, powers, and custom formulas with gradient×covariance steps, correlation options, and Monte Carlo checks.
- Expected Value Simulator
Compare theoretical expected value, variance, and simulated averages for coin flips, dice, or simple lottery-style setups with one shareable browser tool.
- F-Beta Score Calculator
Calculate F-beta from precision and recall, or from TP, FP, and FN.
- Factor Pairs Calculator
Enter a whole number to list every factor and factor pair. Shows divisor count, perfect-square check, prime or composite status, and factor sum.
- First-Order ODE Solver (Separable + Linear)
Solve separable and linear first-order ODEs with slope fields, integrating factors, Simpson integrals, numeric inversion, RK4 checks, and CSV export.
- Fisher Exact Test Calculator
Enter one 2x2 table to read Fisher exact test p-values in two-sided, greater, or less form.
- Fraction calculator
Enter mixed or improper fractions as-is, perform addition, subtraction, multiplication, or division, and instantly view reduced results, mixed-number forms, and decimal output.
- Friedman Test Calculator
Run a Friedman test for 3+ paired groups. Review Q, the p-value, tie correction, Kendall's W, and rank summaries.
- Function Transformations Calculator
Graph function transformations from the parent graph. Adjust a, b, h, and v to compare shifts, stretches, compressions, and reflections.
- GCD & LCM calculator – greatest common divisor tool
Compute the GCD and LCM for up to 32 integers using Euclid’s algorithm and successive reduction.
- GCD & LCM Calculator — step-by-step
Compute GCD (greatest common divisor) and LCM (least common multiple) with steps Euclidean algorithm, ladder method, and extended Euclid.
- Geometry & Graph Tools: Triangles, Vectors, 2D/3D
Solve triangles, work with vectors, and use graph helpers like graph paper and number lines.
- Histogram & cumulative frequency from grouped data
Enter grouped or raw data to build a derived frequency table, histogram (frequency or frequency density), and cumulative frequency ogive.
- How to Do Long Multiplication
Learn long multiplication with short, child-friendly steps. See where to start, why the tens row shifts left, and how to add the final rows.
- Hypergeometric Calculator
Compute exact hypergeometric probabilities without replacement: P(X=k), at most, at least, ranges, mean, variance, PMF table, and simulation.
- Inclusion–Exclusion — at least one & none
Compute |A∪B∪…| (“at least one”) for 2–4 sets. For 2–3 sets you can input Venn regions (easy) or intersection sizes.
- Inequality Solver for 1D & 2D
Solve linear, compound, absolute value, quadratic, and rational inequalities with shareable steps, plus half-plane and system visuals that shade the feasible region.
- Integer composition calculator - counts, k parts
Calculate integer compositions where order matters. Get counts for 2^(n-1), exactly k parts, bounded parts, or nonnegative k parts.
- Integer Partition Calculator (p(n), exactly k parts)
Calculate integer partitions p(n) with options for exactly k parts, max part m, distinct parts, odd/even parts, and bounded ranges.
- Integration Calculator (numeric methods + steps)
Compute definite integrals with trapezoid, Simpson, adaptive, Gaussian, and Monte Carlo methods.
- Inverse Proportion Calculator
Use an inverse proportion calculator for y = k/x. Find k = xy, check constant of proportionality, and sync formula, graph, and table.
- Kruskal-Wallis Test Calculator
Run a Kruskal-Wallis test for 3+ independent groups. Review H, the p-value, tie correction, and rank summaries.
- LaTeX Equation Editor — Live MathJax, palette, templates
An advanced LaTeX equation editor with live MathJax preview, caret-aware palette, templates, history, and one-tap copy/share.
- Likelihood Ratio Calculator
Calculate positive and negative likelihood ratios from TP, FP, TN, and FN.
- Likert Scale Calculator
Paste per-option survey counts and get n, mean, median, mode, standard deviation, Top-2-Box, Bottom-2-Box, NPS split, and distribution bars.
- Limits Explorer — one-sided limits and numeric L'Hôpital
Check indeterminate forms, sample one-sided limits, apply numeric L'Hôpital steps, and view the graph near the approach point.
- Linear Equation Solver (Step by Step)
Linear equation solver that logs each same-operation step. Clear denominators, handle fractions and parentheses, verify the answer, and share URLs or LaTeX/SVG from the browser.
- Linear function y=ax+b explorer
Explore y = ax + b with synchronized formula, table, and graph.
- Linear Regression & Correlation — Scatter, OLS/WLS, R²
Paste x,y[,w] data or upload a CSV to fit OLS, WLS or Theil–Sen regression.
- Linear systems solver – 2×2 and 3×3 equation systems
Solve 2×2 and 3×3 systems of linear equations with Gaussian elimination (RREF), classify solutions, show parametric forms, residuals, and elimination steps.
- Linear Systems Solver with RREF Steps (2×2 & 3×3)
Reduce 2×2 and 3×3 linear systems with Gaussian or Gauss-Jordan elimination, log every row operation, keep exact fractional answers, and share matrices in one click.
- Loan & Mortgage Calculators: Payment, Schedule
Estimate payments, compare amortization schedules, and check affordability (DTI) with browser-only loan & mortgage calculators.
- Log Laws Calculator (with steps) – expand & condense
Expand, condense, and evaluate logarithms with shareable steps.
- Long addition & subtraction (decimal carry/borrow)
Follow column addition or subtraction with decimals, carries, and borrowing one place at a time in a workbook-style layout.
- Long Division Calculator
Enter a dividend and divisor to get long division steps, quotient, remainder, decimal answer, and subtraction work for checking homework.
- Long Multiplication Calculator with Steps
Learn whole-number long multiplication by following partial products, shifted rows, and the final addition step by step.
- Mann-Whitney U Test Calculator
Compare two independent groups with a Mann-Whitney U test. Review exact or asymptotic p-values without assuming normality.
- Matrix Calculator — RREF / Solve Ax=b / Inverse
Compute RREF, solve Ax=b, find the inverse, determinant, rank, null space, row and column spaces with detailed elimination logs.
- MCC Calculator
Calculate Matthews correlation coefficient (MCC), balanced accuracy, precision, recall, specificity, prevalence, and accuracy from TP, FP, TN, and FN for binary classification.
- McNemar Test Calculator
Enter one paired 2x2 table to read exact and asymptotic McNemar test p-values.
- Mean and Standard Deviation Calculator
Paste or type your dataset to compute count, mean, variance, and standard deviation (population N and sample N‑1), then copy a shareable result link.
- Modular arithmetic calculator – GCD, inverse & CRT
Compute extended GCD, modular inverses, fast power, CRT and linear congruences with BigInt precision.
- Multiset permutation calculator
Count distinct permutations when items repeat (anagram count) using n!/(n1!...nk!).
- nCr & nPr Calculator (Permutations & Combinations)
Compute nCr (combinations), nPr (permutations), and factorial (n!).
- Normal Distribution and z-Score Calculator
Calculate normal probabilities, z-scores, percentiles, and inverse cutoffs from the mean and standard deviation.
- NPV & PPV Calculator
Calculate PPV, NPV, sensitivity, specificity, and observed prevalence from TP, FP, TN, and FN, then test how PPV and NPV shift when prevalence changes.
- Number Needed to Harm Calculator
Convert absolute risk increase into number needed to harm and review control risk, exposed risk, and signed risk change together.
- Number Needed to Screen Calculator
Convert screening detection yield into number needed to screen and review prevalence, detection rate, and yield together.
- Odds Probability Converter
Convert probability to odds or odds back to probability. Useful for Bayes updates, likelihood ratios, and diagnostic interpretation.
- Odds Ratio Confidence Interval Calculator
Enter a 2x2 table to read the odds ratio with a 90%, 95%, or 99% confidence interval.
- Odds Ratio from 2x2 Table Calculator
Enter event and non-event counts for two groups to read each group odds and the odds ratio from one 2x2 table.
- Online Dice Roller (d4-d100, 2d6+3)
Roll d4 to d100 or use notation like 2d6+3. See totals and roll breakdowns, keep local history, and share as text or PNG. No sign-in.
- P-value & Critical Value Calculator
Look up p-values from z, t, chi-square, or F statistics, or find critical values from alpha and degrees of freedom with a shaded tail diagram.
- Paint and Coating Calculators
Estimate paint amount (L/gal), coverage, cans, exterior/roof/fence/deck areas, paint cost, and industrial DFT/WFT—browser-only.
- Paper & templates: graph paper, notes, worksheets
Printable paper templates: graph paper, notes, worksheets, and planners.
- Partial fractions calculator – decomposing rational
Decompose rational functions into partial fractions with polynomial long division, Durand-Kerner factorisation, Gaussian elimination, LaTeX, CSV, and shareable URLs.
- Pascal's Triangle & Binomial Expansion (with steps)
Generate Pascal rows, combinations, and binomial expansions with BigInt accuracy.
- Password generator – strong secure random passwords
Generate strong random passwords in your browser with crypto.getRandomValues.
- Pattern String Generator — business IDs & sequences
Generate business-style IDs from a pattern (date, sequence, random).
- Permutation test – exact p-value for A/B and paired
Run a permutation (randomization) test for two independent groups or paired samples.
- Permutations & Combinations with Repetition (n^r, nHr)
Calculate repeated permutations n^r and multichoose values nHr with exact BigInt results or fast scientific-notation approximations.
- Poker Odds Calculator for Texas Hold'em
Calculate Texas Hold'em odds in one place: hand probabilities, outs hit rate, and equity versus random opponents.
- Population Attributable Fraction Calculator
Estimate population attributable fraction and population attributable percent from exposure prevalence and group risk, or from direct attributable risk with total population risk.
- Population Attributable Risk Calculator
Estimate population attributable risk from exposure prevalence and attributable risk, or from exposed and unexposed risk together.
- Population Attributable Risk Percent Calculator
Estimate population attributable risk percent from exposure prevalence with exposed and unexposed risk, or from direct attributable risk with total population risk.
- Post-Test Odds Calculator
Start from pre-test probability or prior odds, apply a likelihood ratio, and review post-test odds and posterior probability together.
- Power Analysis Calculator
Plan required sample size, achieved power, or minimum detectable effect for one mean, two means, one proportion, and two proportions using a fast normal-approximation workflow.
- Powerball & Mega Millions Odds Calculator
Calculate Powerball, Mega Millions, EuroMillions and custom lottery odds: jackpot chance, 1 in X, prize tiers, EV and multi-ticket probability.
- Pre-Test Post-Test Probability Calculator
Convert pre-test probability into post-test probability with LR+ or LR-.
- Precision & Recall Calculator
Calculate precision, recall, F1, specificity, prevalence, and accuracy from TP, FP, TN, and FN.
- Prime factorization calculator – exponents, divisors
Factor any positive integer into primes, see exponents, divisor counts, the largest prime factor, and copy a shareable result link for homework or quick checks.
- Print DPI Calculator
Estimate effective PPI for a print size from image pixels. Compare horizontal, vertical, and target PPI before resizing or ordering a print.
- Probability & simulation tools
Probability simulators and calculators for expected value, trees, combinatorics, distributions, and Monte Carlo intuition.
- Probability tree & 2×2 table — AND/OR & complement
Probability tree & 2×2 table tool for AND/OR/NOT and complements.
- Pythagorean theorem calculator
Solve and visualize a²+b²=c² with a right-triangle diagram. Find a side, test a triangle, or measure distance with exact radicals and steps.
- Random & Lotteries: Pickers, Dice, Probability
Find the right random tool fast: weighted random picker, random picker, dice tools, plus probability calculators.
- Random CSV generator – test data & schema JSON
Generate random CSV test data in your browser. Define columns, preview rows, then download CSV and schema JSON — no uploads and share settings-only URLs.
- Random Date Generator, Time Generator & Datetime Generator
Generate random dates, random times, or random datetimes with ranges, weekday filters, exclusions, time windows, and step sizes for QA, test data, or schedule sampling.
- Random distributions: samplers, tests & visualizers
Generate random samples from distributions, visualize histograms, and sanity-check randomness in your browser.
- Random JSON Generator (Test Data) — array & NDJSON
Generate JSON test data from a schema. Export as JSON array or NDJSON. Runs locally in your browser — no uploads; share settings-only URLs.
- Random Log Generator — Nginx, Apache & JSON logs
Generate fake access logs (Nginx/Apache) or JSONL logs with controllable distributions.
- Random number generator (integers, decimals, seed)
Generate random numbers in your browser: integers or decimals, optional seed, unique mode, and one-click copy.
- Random Picker
Pick one or more random items from a list in your browser. Great for lotteries, giveaways, and classroom activities. Everything runs locally without sending data to a server.
- Random SQL INSERT Generator — Postgres, MySQL, SQLite
Generate SQL INSERT statements from a schema for Postgres, MySQL, or SQLite.
- Random test data generators (CSV, IDs, time)
Create CSV test data, random IDs, and timestamps locally in your browser.
- Random tools – generators, pickers, shuffles
Random generators and pickers that run entirely in your browser: numbers, dates, CSV test data, tokens, UUIDs, shuffles, and verifiable draws.
- Random Walk & Markov Chain Visualizer
Run random walk (1D/2D/3D) and Markov chain simulations in your browser.
- Randomness beacon verifier – paste a beacon to verify
Paste a public beacon value to verify a deterministic draw or shuffle.
- Randomness Tests (chi-square, runs, ACF, JB)
Run chi-square, runs, autocorrelation, and Jarque-Bera tests on bit or number sequences.
- Ratio Calculator & Proportion Solver with Steps
Use a ratio calculator and proportion solver with steps. Simplify ratios, solve a:b=c:d, convert percent proportions, split totals, and share worked examples.
- Real Estate (Mortgage/Amortization/Affordability)
Estimate mortgage payments, amortization schedules, and affordability (DTI) together.
- Relative Risk and Odds Ratio Calculator
Enter event and non-event counts for two groups to compare relative risk, odds ratio, and absolute risk difference in one place.
- Repeating Decimal to Fraction Calculator with Steps
Convert repeating (recurring) decimals like 0.1666... or 0.(142857) into exact reduced fractions with 10^k algebra steps, GCD simplification, and a reverse check.
- Riemann Sums Calculator
Visualize left/right, midpoint, trapezoid and Simpson sums for f(x), compare with an adaptive Simpson reference, and export CSV or share a link.
- Risk Difference Calculator
Compare two event-rate groups and review signed risk difference, absolute difference, and each group risk together.
- Risk Difference Confidence Interval Calculator
Enter one 2x2 table to read the risk difference with a 90%, 95%, or 99% confidence interval.
- Risk Ratio Confidence Interval Calculator
Enter a 2x2 table to read the risk ratio with a 90%, 95%, or 99% confidence interval.
- Risk Ratio from 2x2 Table Calculator
Enter event and non-event counts for two groups to read each group risk, the risk ratio, and risk difference from one 2x2 table.
- ROC AUC Calculator
Calculate a binary ROC curve, AUC, and threshold table from pasted score,label rows.
- Roman Numeral Converter
Convert integers to Roman numerals and Roman numerals back to numbers.
- Rounding & error bands
Round any number, highlight the digit you inspect, and see the error band on a number line.
- Sample Size Calculator
Plan sample size for surveys, means, and balanced A/B tests.
- Sampling & Bootstrap — CLT Explorer (with steps)
Simulate samples from common distributions, bootstrap means or proportions, and see CLT histograms with steps explanations for classroom demos.
- Scientific calculator – trig, logs, powers and degree
Run trig, logs, exponents, and factorials with Deg/Rad modes, keyboard input, memory, and a shareable URL that preserves your expression and settings.
- Seating Chart Generator (Random) — Classroom & Tables
Free online seating chart generator for classrooms and events.
- Sector arc length, area & angle calculator
Solve a sector’s arc length l, area A, central angle θ, or radius r with units and a live diagram.
- Sensitivity and Specificity Calculator
Calculate sensitivity, specificity, false positive rate, false negative rate, balanced accuracy, and prevalence from TP, FP, TN, and FN for one binary threshold.
- Sequences & Series (Arithmetic / Geometric) — terms
Compute arithmetic and geometric sequences with steps logs: nth terms, partial sums, solving for n or k, two-point inference, and table generation with shareable outputs.
- Shuffle bias comparison – naive vs Fisher–Yates
Compare shuffle bias: naive swap-everywhere vs Fisher–Yates (and optional sort(() => random - 0.5)).
- Sign Test Calculator
Run an exact sign test on paired before/after values. Use it when only the direction of paired change matters and zero differences should be ignored.
- Signed number line calculator & sign rules
Add, subtract, multiply, and divide signed numbers with a number-line animation for plus/minus moves.
- Similarity ratio calculator – side, area, volume
Enter a similarity ratio (small:large) to see side/perimeter, area (square), and volume (cube) ratios with scale factors.
- Simultaneous Equations Solver (steps + graph)
Solve two linear equations with elimination, substitution, and graph views.
- Square root simplifier with factor tree & steps
Simplify square roots to a√b with factor tree, pairing highlights, and steps.
- Standard calculator (history tape & memory)
Perform four‑function math with parentheses and percent, a running tape, and memory slots—fully keyboard accessible, with a shareable result link.
- Stars and Bars Calculator
Use the stars and bars method to count combinations with repetition.
- Statistics (inference & tests)
Inference tools for confidence intervals, hypothesis tests, regression, and uncertainty.
- Statistics & Probability (overview): Inference
Overview hub for statistics & probability. For focused lists, open Inference & tests, Probability & simulation, or Data visualization.
- Stirling Numbers Calculator (1st & 2nd Kind)
Generate Stirling numbers of the first and second kind, plus Bell numbers, with fast table output, recurrence details, and downloadable values for study or coding tasks.
- Streak Probability Simulator
Estimate the chance of consecutive wins or losses, expected streak starts, and likely longest streaks in one browser-only calculator.
- Study & Classroom Tools: Worksheets, Graph Paper, GPA
Classroom-ready tools: worksheet generator, graph paper, quick charts, plus GPA and stats calculators.
- Surface & volume nets
Compute surface area and volume for prisms, pyramids, cylinders, cones, and spheres with net diagrams, face breakdowns, units, examples, and formula steps.
- Synthetic Time Series Generator — trend, seasonality
Generate synthetic time series data with trend, seasonality, noise, missing values, and outliers.
- T-Test Calculator
Run one-sample, two-sample, and paired t-tests from summary statistics or pasted raw data.
- Tax Calculators: VAT, GST, Income Tax, Net ↔ Gross
Quick tax calculators for VAT/GST, net↔gross conversions, and income tax.
- Taylor & Maclaurin Series — with steps and graphs
Build Taylor and Maclaurin polynomials P_n(x) with symbolic derivatives or fallback fits, then compare f and P_n on one graph.
- Team generator – random teams & groups
Split a list of names into random teams or groups in your browser.
- Topic hubs for calculators and tools
Choose a task first, then open the topic hub that narrows calculators and tools for money, study, time, conversion, PDF work, and more.
- Triangle Solver (SSS / SAS / ASA, Area & Circumradius)
Select SSS, SAS, or ASA inputs and compute the remaining sides, angles, area, and triangle diagram.
- Triangle Solver (SSS, SAS, ASA, SSA) with steps
Solve a triangle from sides and angles with SSS, SAS, ASA/AAS, or SSA.
- Triangular Distribution Generator (min/mode/max)
Generate samples from a triangular distribution using min/mode/max and visualize the PDF and histogram.
- TRPG dice check (d20/d100, pools) with PNG sharing
Run d20/d100 checks with advantage/disadvantage, compare vs DC, and roll dice pools to count successes.
- Truncated Normal Generator & Visualizer
Generate samples from a truncated normal distribution with lower/upper bounds and visualize the PDF/CDF and histogram.
- Truth Table & Logic Evaluator — DNF/CNF Simplifier
Build Boolean truth tables up to 10 variables, export canonical DNF/CNF, simplify with Karnaugh or Quine–McCluskey, and share CSV or URL with How it’s calculated steps.
- Unit Circle & Trig Explorer — amplitude, period & phase
Explore y = A·f(bx+φ)+D for sine, cosine, and tangent.
- Vector Calculator — dot/cross, projection, angle, area
Compute norms, dot, cross (2D/3D), projection, angle, areas, and triple product with steps logs.
- Verifiable random draw (commit-reveal) – auditable
Run a verifiable random draw with commit-reveal logs so participants can verify every draw.
- Weibull Distribution Generator & Visualizer
Generate random samples from a Weibull distribution and visualize the PDF and histogram.
- Weighted Random Picker & Randomizer
Use this weighted random picker and randomizer to draw winners by weight, ratio, or raffle entries.
- Wilcoxon Signed-Rank Test Calculator
Enter paired before and after values to run a Wilcoxon signed-rank test.
- Word Problem Wizard — percent, ratio, speed
Solve common word problems by selecting a template, entering values with units, and getting equations and simple diagrams.
- Youden’s J Calculator
Calculate Youden’s J from TP, FP, TN, and FN. Review sensitivity, specificity, false-positive rate, false-negative rate, and balanced accuracy at one threshold.
FAQ
Which math or statistics calculator should I open first?
Start from the result you need: percentage, equation solving, graphing, probability, descriptive statistics, or a table. The directory links are grouped so you can move from a broad topic to a specific calculator.
When should I use a statistics page instead of a general calculator?
Use a statistics page when the input is a dataset, frequency table, probability model, confidence interval, or hypothesis test. Use a general math calculator for algebraic expressions, geometry, or unit-style numeric work.
Are these pages suitable for homework checks?
Yes, they are useful for checking arithmetic, formulas, and steps. Still compare the displayed method with your class notation because teachers may require a specific rounding or explanation style.
How should I compare results across calculators?
Keep the same data, units, rounding, and sample-versus-population convention. Differences often come from using sample standard deviation in one place and population standard deviation in another.
Do the calculators upload my data?
Core calculations run in the browser. Share links can include parameters only when you choose to copy or share a URL.
Choosing a math or statistics tool
Start from the task
For algebra, choose a solver or simplifier. For geometry, choose a shape or coordinate calculator. For statistics, choose the page that matches the data structure and inference question.
Check conventions
Math and statistics pages may use different rounding, exact forms, sample/population conventions, or interval definitions. Read the result labels before copying an answer.
Use step pages for learning
Pages with step logs are best for classroom checks because they show substitutions and formulas. Directory pages are best when you are still choosing the right workflow.
Common mistakes
Do not paste a table into a single-value calculator. Do not compare probability, frequency, and percentage outputs without confirming the denominator.
Next move
If the directory feels too broad, open the closest topic hub first, then move to the calculator with the exact input fields you need.