134 free tools · Private · In-Browser

Math & Numbers Tools

Math calculators that show their work: factor quadratics, find determinants and dot products, run z-tests and confidence intervals, compute factorials and prime factorizations, and solve sequences and proportions. Useful for homework checks and quick work calculations alike.

Factorial Calculator

Free factorial calculator that uses big integers to compute n! exactly for large n without rounding or scientific notation, in your browser.

Extended Euclidean Calculator

Free extended Euclidean calculator that returns the gcd and Bézout coefficients for two integers, verifies the identity, and runs in your browser.

Fraction Simplifier

Free fraction simplifier that converts values instantly in your browser. Includes examples, formulas, limits, copy-ready output, and local privacy.

Midpoint Calculator

Free midpoint calculator: enter two points to get the coordinates of the point exactly halfway between them, computed locally in your browser.

3D Distance Calculator

Free 3d distance calculator with labeled inputs and an immediate result. It finds straight-line distance between spatial points privately in your browser.

Combinations & Permutations Calculator

Free nCr and nPr calculator: enter n and r to get combinations and permutations without overflowing on large factorials, in your browser.

Conditional Probability Calculator

Free conditional probability calculator: find P(A given B) from the joint and marginal probabilities, in your browser.

Difference of Means CI

Free difference of means confidence interval calculator using two means, standard deviations, sample sizes, and z level privately in your browser.

Matrix Determinant Calculator

Free matrix determinant calculator using pivoted elimination for square matrices, with singularity detection and sign tracking in your browser.

Mean, Median & Mode Calculator

Free mean, median, and mode calculator: paste numbers to get the average, middle value, most common value, range, count, and sum in your browser.

Percent Error Calculator

Free percent error calculator: compare a measured value to the true value and get the percentage error, computed in your browser.

Percent of Total Calculator

Free percent of total calculator: find what percentage one number is of another, computed in your browser.

Prime Factorization Calculator

Free prime factorization calculator: enter a whole number to break it into its prime factors with exponents, computed locally in your browser.

Right Triangle Calculator

Free right triangle calculator: find the hypotenuse, area, and angles from two legs, in your browser.

Sample Excess Kurtosis

Free sample excess kurtosis calculator using the unbiased Fisher correction to compare tail weight with a normal model privately in your browser.

Sample Skewness Calculator

Free sample skewness calculator using the adjusted Fisher-Pearson coefficient to quantify asymmetry in pasted data, entirely in your browser.

Welch Two-Sample T-Test

Free Welch two-sample t-test calculator for two numeric samples, returning means, t statistic, degrees of freedom, and p range in your browser.

2x2 Equation Solver

Solve two linear equations in two unknowns with Cramer's rule, view the determinant, and check each solution privately in your browser without uploads.

Arithmetic Sequence Calculator

Free arithmetic sequence calculator: find the nth term and the sum of the series from the first term and common difference, in your browser.

Armstrong Number Checker

Free Armstrong number checker that raises each decimal digit to the digit count, totals the powers, and verifies the number in your browser.

Chi-Square Independence Test

Free chi-square independence calculator for a contingency table, returning expected counts, statistic, and degrees of freedom in your browser.

Chinese Remainder Theorem Solver

Free Chinese remainder theorem solver for simultaneous congruences with pairwise coprime moduli, verified and calculated privately in your browser.

Cylinder Volume Calculator

Free cylinder volume calculator: find the volume and surface area of a cylinder from radius and height, in your browser.

Dice Probability Calculator

Free dice probability calculator: find the odds of rolling a target sum with any number of dice, in your browser.

Divisors Calculator

Free divisors calculator that lists every positive factor of an integer and reports divisor count, sum, and proper divisors in your browser.

Fibonacci Sequence Generator

Free Fibonacci sequence generator using big integers to list exact terms and the golden-ratio approach, computed locally in your browser.

GCD & LCM Calculator

Free GCD and LCM calculator: paste a list of whole numbers to get their greatest common divisor and least common multiple in your browser.

Geometric Mean Calculator

Free geometric mean calculator: find the geometric mean of a set of positive numbers, in your browser.

Odds & Probability Converter

Free odds to probability converter: switch between odds, probability, and percentage, computed in your browser.

One-Way ANOVA Calculator

Free one-way ANOVA calculator comparing three or more numeric groups with between, within, degrees of freedom, and F output in your browser.

Parallelogram Area Calculator

Free parallelogram area calculator: find the area from base and perpendicular height, in your browser.

Quadratic Equation Solver

Free quadratic equation solver: enter a, b, and c to get the real or complex roots, the discriminant, and the vertex, right in your browser.

Rectangular Prism Calculator

Free rectangular prism calculator: find the volume, surface area, and diagonal from length, width, and height, in your browser.

Triangular Number Calculator

Free triangular number calculator with labeled inputs and an immediate result. It calculates the nth triangular number privately in your browser.

3x3 System of Equations Solver

Free 3x3 system of equations solver using Cramer determinants to find x, y, and z from an augmented matrix, calculated privately in your browser.

Binomial Probability Calculator

Free binomial probability calculator: find the chance of k successes in n trials at probability p, in your browser.

Chi-Square Goodness-of-Fit

Free chi-square goodness-of-fit with labeled inputs and an immediate result. It compares observed and expected category counts privately in your browser.

Class Attendance Percent Calculator

Calculate meetings attended and missed from total meetings and an attendance rate. It runs entirely in your browser — no uploads or accounts.

Cohen D Effect Size Calculator

Free cohen d effect size calculator with labeled inputs and an immediate result. It standardizes a two-group mean difference privately in your browser.

Combinations with Repetition

Free combinations with repetition calculator: count multiset selections from n items, in your browser.

Cube Volume Calculator

Free cube volume calculator: find the volume, surface area, and diagonal of a cube from its side, in your browser.

Derangement Calculator

Free derangement calculator that counts permutations with no fixed positions using an exact recurrence for n from zero through 18 in your browser.

Difference of Proportions CI

Free difference of proportions confidence interval calculator from two success counts and sample sizes with selected confidence in your browser.

Discriminant Calculator

Free discriminant calculator with labeled inputs and an immediate result. It classifies quadratic roots from coefficients privately in your browser.

Final Grade Calculator

Free final grade calculator: find the score you need on the final exam to reach your target grade, in your browser.

Five Number Summary Calculator

Free five number summary calculator: find the minimum, quartiles, median, and maximum of a data set, in your browser.

Geometric Distribution Calculator

Free geometric distribution calculator with an immediate result. It calculates first-success probability and cumulative chance privately in your browser.

Happy Number Checker

Free happy number checker that repeats squared-digit sums, displays the path, and detects either one or a repeating cycle entirely in your browser.

Hypergeometric Distribution

Free hypergeometric distribution calculator for exactly k successes when sampling without replacement from a finite population in your browser.

Linear Regression Calculator

Free linear regression calculator: fit a least-squares line to your x,y points and get slope, intercept, and R-squared, in your browser.

Lottery Odds Calculator

Free lottery odds calculator: find the odds of matching all numbers in a pick-k-from-n lottery, in your browser.

Matrix Transpose Calculator

Free matrix transpose calculator that swaps rows and columns for any rectangular numeric matrix and shows the new dimensions in your browser.

Median Absolute Deviation

Free median absolute deviation calculator that finds the median, absolute residuals, and robust MAD for pasted numeric data in your browser.

Modular Inverse Calculator

Free modular inverse calculator that finds an integer inverse modulo m, with labeled assumptions and an immediate result calculated privately in your browser.

Normal Distribution Calculator

Free normal distribution calculator returning z score, density, lower cumulative probability, and upper tail for x, mean, and SD in your browser.

Normal Distribution CDF

Free normal distribution cdf with labeled inputs and an immediate result. It estimates cumulative normal probability below x privately in your browser.

One-Sample Mean Z-Test

Free one-sample mean z-test calculator using sample mean, hypothesized mean, known population deviation, and n with p value in your browser.

Outlier Detector

Free outlier detector: flag outliers in a data set using the 1.5 IQR rule, computed locally in your browser.

Percentile Rank Calculator

Free percentile rank calculator with labeled inputs and an immediate result. It finds rank from counts below and equal privately in your browser.

Probability Calculator

Free probability calculator: find the probability of an event from favorable and total outcomes, in your browser.

Proportion Calculator

Free proportion calculator: solve a/b = c/d for the missing value by cross-multiplication, in your browser.

Range Calculator

Free range calculator: find the range, minimum, maximum, and midrange of a data set, in your browser.

Significant Figures Calculator

Free significant figures calculator: round a number to a chosen number of significant figures, in your browser.

Slope Calculator

Free slope calculator: find the slope, angle, and equation of a line through two points, computed locally in your browser.

Sphere Volume Calculator

Free sphere volume calculator: find the volume and surface area of a sphere from its radius, in your browser.

Standard Error Calculator

Free standard error of the mean calculator from a data set, computed locally in your browser.

Stirling Number Calculator

Free Stirling number of the second kind calculator counting partitions of n labeled objects into k nonempty unlabeled groups in your browser.

Sum of Squares Calculator

Free sum of squares calculator: find the total sum of squared deviations from the mean, in your browser.

Synthetic Division Calculator

Free synthetic division calculator that divides polynomial coefficients by x minus k and reports the quotient and remainder instantly in your browser.

Two-Variable Covariance Calculator

Free two-variable covariance calculator with an immediate result. It calculates population covariance for paired summaries privately in your browser.

Variance Calculator

Free variance calculator: find the sample and population variance and standard deviation of a data set, in your browser.

Weighted Grade Calculator

Free weighted grade calculator: combine assignment scores and their weights into an overall grade, in your browser.

Catalan Number Calculator

Free catalan number calculator that computes a Catalan sequence value, with labeled assumptions and an immediate result calculated privately in your browser.

Circle Calculator

Free circle calculator: find area, circumference, and diameter from a radius, computed locally in your browser.

Circle Sector Area Calculator

Free circle sector calculator: find the area and arc length of a sector from radius and angle, in your browser.

Coefficient of Variation Calculator

Free coefficient of variation calculator: find relative variability as a percentage of the mean, in your browser.

Color Gradient Midpoint Finder

Compute the midpoint color between two hex colors and preview the three-stop gradient. Free and private in your browser, with nothing uploaded and no account.

Complete the Square Calculator

Free complete the square calculator with labeled inputs and an immediate result. It rewrites a monic quadratic in vertex form privately in your browser.

Cone Volume Calculator

Free cone volume calculator: find the volume, slant height, and surface area of a cone, in your browser.

Correlation Calculator

Free Pearson correlation coefficient calculator: measure the linear relationship between two data sets, computed in your browser.

Correlation Matrix Calculator

Free correlation matrix calculator that treats each line as a variable and returns every Pearson pairwise coefficient privately in your browser.

Cross Product Calculator

Free cross product calculator for two three-dimensional vectors, returning the perpendicular vector and its magnitude directly in your browser.

Cubic Equation Solver

Free cubic equation solver using the depressed-cubic method to find every real root from four coefficients, computed privately in your browser.

Cumulative GPA Calculator

Free cumulative GPA calculator: combine your prior GPA with a new semester into an overall GPA, in your browser.

Digital Root Calculator

Free digital root calculator with labeled inputs and an immediate result. It reduces an integer through repeated digit sums privately in your browser.

Dot Product Calculator

Free dot product calculator that multiplies matching vector components, adds the products, and checks equal dimensions privately in your browser.

Ellipse Area Calculator

Free ellipse area calculator: find the area and approximate circumference from the two radii, in your browser.

Euler Totient Calculator

Free euler totient calculator that counts positive integers coprime to n, with labeled assumptions and an immediate result calculated privately in your browser.

Expected Value Calculator

Free expected value calculator: find the mean outcome from values and their probabilities, in your browser.

Exponential Distribution Calculator

Free exponential distribution calculator with labeled inputs and an immediate result. It calculates waiting-time density and CDF privately in your browser.

Grouped Data Mean Calculator

Free grouped data mean calculator using class midpoints and frequencies to return the weighted total, sample count, and mean in your browser.

Hexagon Area Calculator

Free regular hexagon area calculator: find the area and perimeter from the side length, in your browser.

Letter Grade Calculator

Free letter grade calculator: convert a percentage into a letter grade and GPA points, computed in your browser.

Logarithm Calculator

Free logarithm calculator: compute the log of a number in any base, plus natural and base-2 logs, in your browser.

Matrix Inverse Calculator

Free matrix inverse calculator using pivoted Gauss-Jordan elimination for nonsingular square matrices, with clean private output in your browser.

Mean Confidence Interval

Calculate a z-based confidence interval for a sample mean from its standard deviation, sample size, and critical value in your browser without uploads.

Multinomial Coefficient

Free multinomial coefficient calculator for category counts, showing total factorial over each group factorial with exact output in your browser.

Numeric Derivative Calculator

Free numeric derivative calculator using a central difference for common functions at any x value and positive step size, directly in your browser.

Percent of a Number Calculator

Free percent of a number calculator: find what a percentage of a number is, computed locally in your browser.

Percentage Decrease Calculator

Free percentage decrease calculator: find the percent drop from one value to another, computed in your browser.

Percentage Increase Calculator

Free percentage increase calculator: find the percent growth from one value to another, computed in your browser.

Percentile Calculator

Free percentile calculator: find the value at any percentile of a data set by interpolation, in your browser.

Poisson Probability Calculator

Free Poisson probability calculator: find the chance of k events given an average rate, in your browser.

Prime Number Checker

Free prime number checker: test whether a number is prime, see a factor if it is not, and find the next prime — all locally in your browser.

Proportion Confidence Interval

Free proportion confidence interval with labeled inputs and an immediate result. It estimates a z interval around a sample proportion privately in your browser.

Pyramid Volume Calculator

Free pyramid volume calculator: find the volume of a square pyramid from base and height, in your browser.

Quadratic Factoring Calculator

Free quadratic factoring calculator that finds real roots and writes a polynomial as linear factors from a, b, and c entirely in your browser.

Quartile Calculator

Free quartile calculator: find Q1, Q2, Q3, and the interquartile range of a data set, in your browser.

Quiz Curve Points Calculator

Calculate a curved score by adding curve points to a raw score. Everything is computed locally in your browser, with no uploads and no sign-ups.

Random Table Range Calculator

Calculate how many die rolls cover a random table from entries and die faces. Everything is calculated locally in your browser, with no uploads or sign-ups.

Relative Risk Calculator

Free relative risk calculator from two cohort event tables, returning both group risks, risk ratio, and risk difference privately in your browser.

Semester Credit Load Calculator

Calculate total semester credits from a course count and credits each. Everything is calculated locally in your browser, with no uploads or sign-ups.

Simplify Fractions Calculator

Free simplify fractions calculator that reduces an integer fraction to lowest terms. Review labeled assumptions and a worked result calculated privately in your browser.

Standard Deviation Calculator

Free standard deviation calculator with population and sample options, reporting mean, variance, and spread from any list of numbers in your browser.

Thin Lens Equation Calculator

Free thin lens equation calculator with labeled inputs and an immediate result. It finds image distance and magnification privately in your browser.

Trapezoid Area Calculator

Free trapezoid area calculator: find the area from the two parallel sides and the height, in your browser.

Triangle Area Calculator

Free triangle area calculator using Heron’s formula from three sides, with perimeter, computed locally in your browser.

Uniform Distribution Calculator

Free uniform distribution calculator with labeled inputs and an immediate result. It finds interval probability under a uniform model privately in your browser.

Z-Score Calculator

Free z-score calculator: find how many standard deviations a value sits from the mean, computed locally in your browser.

Z-Score to Percentile Calculator

Free z-score to percentile calculator: convert a z-score to its percentile under the normal curve, in your browser.

Additive Grade Curve

Free additive grade curve calculator that shifts every score by the same points until the highest reaches 100, calculated privately in your browser.

Base-N Converter

Free base-N number converter: convert a number between any bases from 2 to 36, computed locally in your browser.

Collatz Sequence Calculator

Free Collatz sequence calculator that applies the odd and even rules, lists every term, and reports step count and peak privately in your browser.

Distance Between Two Points

Free distance calculator for two points on a plane: enter coordinates to get the straight-line distance and the horizontal and vertical gaps in your browser.

Geometric Sequence Calculator

Free geometric sequence calculator: find the nth term and sum from the first term and common ratio, computed in your browser.

GPA Calculator

Free GPA calculator: find your grade point average from course grades and credits on the 4.0 scale, in your browser.

GPA Quality Points Calculator

Calculate quality points from grade points and credit hours. Everything is computed locally in your browser, with no uploads and no sign-ups.

Harmonic Mean Calculator

Free harmonic mean calculator: find the harmonic mean of a set of numbers, computed locally in your browser.

Matrix Multiplication

Free matrix multiplication calculator that parses two matrices, checks compatible dimensions, and computes every row-column product in your browser.

Perfect Number Checker

Free perfect number checker that lists proper divisors, adds them, and tests whether their sum equals the positive integer privately in your browser.

Pythagorean Theorem Calculator

Free Pythagorean theorem calculator: enter any two sides of a right triangle to solve the third using a² + b² = c², in your browser.

Test Grade Calculator

Free test grade calculator: turn correct answers out of a total into a percentage and letter grade, in your browser.

Fraction Calculator

Free fraction calculator: add, subtract, multiply, or divide fractions and mixed numbers, simplified, with every step shown.

Odds Calculator

Free odds calculator: turn a stake and American, decimal, or fractional odds into payout, profit, and implied probability.