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Math and Statistics Calculators
Arithmetic, algebra, geometry, probability and statistics tools that show their working.
From fractions and factors to standard deviation and confidence intervals, these calculators show the working as well as the answer, so they help you learn the method and not only copy the result.
Percentage CalculatorPercent of a number, percent change, and increase or decrease by a percent, with working.Scientific CalculatorEvaluate typed expressions with trig, logs, roots, powers and factorials in degrees or radians.Fraction CalculatorAdd, subtract, multiply and divide fractions and mixed numbers with simplified, mixed and decimal answers.Random Number GeneratorGenerate random integers or decimals in a range, with or without repeats, using secure randomness.Triangle CalculatorSolve triangles from SSS, SAS or ASA/AAS and get angles, area, perimeter, inradius and type.Standard Deviation CalculatorPopulation and sample standard deviation, variance, mean, sum, count and standard error for a list of numbers.Mean, Median, Mode CalculatorMean, median, mode, range, quartiles and IQR for a list of numbers, with the quartile method stated.Average CalculatorSimple mean, weighted average, and the score needed on remaining work to reach a target average.Ratio CalculatorSimplify ratios, solve A:B = C:x for the missing term, or split a total in a given ratio.GCF CalculatorGreatest common factor (GCD) of two or more whole numbers, with Euclidean algorithm steps.LCM CalculatorLeast common multiple of two or more whole numbers, with prime factors and the matching GCF.Prime Factorization CalculatorPrime factors of a whole number up to 10^12, with divisor count, divisor sum and a factor table.Prime Number CheckerTest whether a whole number up to 19 digits is prime, with smallest factor and neighbouring primes.Quadratic Formula CalculatorSolve ax² + bx + c = 0: real or complex roots, discriminant, vertex, axis and factored form.Pythagorean Theorem CalculatorFind the hypotenuse or a leg of a right triangle, with area, perimeter, angles and triple check.Exponent CalculatorRaise a base to any power: whole, negative or fractional, with exact integers and scientific notation.Square Root CalculatorSquare, cube and nth roots with simplified radical form and perfect-power check.Logarithm CalculatorLog base 10, ln, log base 2 or any base, plus antilog, with change-of-base working.Scientific Notation CalculatorConvert numbers to scientific, E and engineering notation, or back to a plain decimal.Significant Figures CalculatorCount significant figures in a number or round to N significant figures, using the standard rules.Rounding CalculatorRound to any decimal place, ten or hundred with half-up, banker's, floor, ceiling or truncate.Factorial CalculatorExact n! and n!! up to 1,000, with digit count, trailing zeros and a Stirling check.Sample Size CalculatorHow many people to survey for a chosen confidence level and margin of error (Cochran).Base ConverterConvert numbers between bases 2 to 36: binary, octal, decimal, hex and others.Roman Numeral ConverterConvert numbers 1 to 3999 to Roman numerals and back, with a breakdown of each symbol.Number Sequence CalculatorNth term, sum and listed terms of arithmetic and geometric sequences, with pattern detection.Matrix CalculatorDeterminant, inverse, transpose, addition and multiplication of matrices up to 4 by 4.Long Division CalculatorQuotient, remainder, repeating decimals and the step-by-step working of long division.Percent Error CalculatorPercent error, absolute and signed error for a measurement, plus percent difference of two values.Half-Life CalculatorRemaining amount, elapsed time or half-life for exponential decay, with decay constant.Linear Regression CalculatorLeast-squares line of best fit with slope, intercept, correlation r, R squared and prediction.Decimal to Fraction CalculatorConvert terminating and repeating decimals to simplified fractions, or approximate with a denominator limit.Fibonacci CalculatorExact nth Fibonacci number, sequence list with golden-ratio convergence, and a Fibonacci checker.Slope CalculatorSlope, line equation, y-intercept, angle and perpendicular slope from two points.Distance CalculatorStraight-line distance between two points in 2D or 3D, with working and taxicab distance.Midpoint CalculatorMidpoint of a segment from two endpoints, or the missing endpoint from one end and the midpoint.Area CalculatorArea (and perimeter where possible) of squares, triangles, circles, trapezoids, polygons and more.Volume CalculatorVolume of cubes, boxes, cylinders, spheres, cones, pyramids and more, in litres and gallons too.Surface Area CalculatorTotal and lateral surface area of cubes, boxes, cylinders, spheres, cones, pyramids and frustums.Circle CalculatorRadius, diameter, circumference and area from any one value, with arc, sector and chord.Permutation and Combination CalculatorExact nPr, nCr and with-repetition counts for n up to 1,000, using big-integer arithmetic.Probability CalculatorSingle-event odds, two-event and/or rules, and exact binomial probabilities with working.Z-Score CalculatorZ-score, percentile, tail probabilities and two-tailed p-value from the standard normal curve.Confidence Interval CalculatorConfidence interval for a mean (z or t) or a proportion (Wald and Wilson) with margin of error.
Accuracy note: Results use standard double-precision arithmetic, so very large or very small values may be rounded. Check important results by another method.