Math Calculators
Percentages, ratios and everyday math, each with the formula written out.
Area CalculatorCalculate area for a rectangle, circle, triangle, or trapezoid. Each shape uses its standard formula, with an exact value of π for circles.Average CalculatorPaste a list of numbers to get the mean, median, mode, range, minimum, maximum, sum, and count in one step. Handles even-count and multi-modal sets.Big Number CalculatorAdd, subtract, multiply, divide, raise to a power, or take the modulo of integers of any size, exact to the last digit, using arbitrary-precision BigInt math.Circle CalculatorEnter a circle's radius, diameter, circumference, or area and get all four measurements instantly. A radius of 5 gives a circumference of 10π ≈ 31.42.Combinations and Permutations CalculatorCalculate nCr combinations, nPr permutations, and n! factorial for any n up to 170. A 5-card hand from a 52-card deck has exactly 2,598,960 combinations.Confidence Interval CalculatorConfidence interval calculator using sample mean, standard deviation and n. Get the margin of error and interval at 90%, 95% or 99% using the z-value.3D Distance CalculatorFind the straight-line distance between two 3D points, plus the midpoint, per-axis deltas, and vector magnitude. Example: (1,2,3) to (4,6,15) is exactly 13.Exponent CalculatorRaise any base to a positive, negative, or fractional exponent. See 2^10 = 1,024 and 9^0.5 = 3, with large or tiny results shown in scientific notation.Factor CalculatorFind every factor of a number, its factor pairs, factor count and sum, plus whether it is prime or a perfect number. Supports whole numbers up to 1e12.Fraction CalculatorAdd, subtract, multiply, or divide two fractions, or simplify one fraction to lowest terms. See the result as a fraction, mixed number, and decimal.GCF and LCM CalculatorFind the GCF and LCM of two or more numbers, plus the prime factorization of each. GCF(12,18) = 6 and LCM(4,6) = 12, shown with every prime factor.GPA CalculatorCalculate your GPA on the standard US 4.0 scale from a list of letter grades and credit hours. Enter A through F, with plus and minus grades supported.Half-Life CalculatorHalf-life calculator for exponential decay. Solve for the remaining amount, the elapsed time, or the half-life itself, using N = N0 x (1/2)^(t / half-life).Log CalculatorCalculate a logarithm in any base, the natural log (ln), or the common log (base 10). Log base 2 of 8 is 3, since 2^3 = 8, checked with change of base.Long Division CalculatorDivide two whole numbers and see the full long-division steps: bring down, multiply, subtract, and remainder, plus the quotient and decimal result.Matrix CalculatorAdd, subtract, multiply, transpose, or invert a matrix, with clear dimension-mismatch and singular-matrix error messages.Modulo CalculatorModulo calculator showing both the floored modulo (math convention) and the JavaScript % remainder. For -7 mod 3, floored gives 2 while JS % gives -1.Percent Error CalculatorCalculate percent error between a measured and actual value, both as an absolute percentage and a signed over/underestimate. 9.8 vs 10 is a 2% error.Percentage CalculatorFree percentage calculator: find what X% of a number is, what percent one number is of another, and percent increase or decrease, with worked examples.Prime Number CalculatorCheck if a number is prime, see its prime factorization, and find the next and previous prime. 97 is prime, 561 = 3x11x17, next prime after 100 is 101.Probability CalculatorCalculate the probability of a single event, two independent events (and/or), or a complement, plus the equivalent odds. Rolling a 6-sided die is 1/6.Pythagorean Theorem CalculatorFind the hypotenuse from two legs, or a missing leg from the hypotenuse and one leg. Get the right triangle's perimeter and area with a² + b² = c² shown.Quadratic Equation CalculatorSolve ax² + bx + c = 0 instantly. Get both roots (real or complex), the discriminant, and the parabola's vertex, with each quadratic formula step shown.Quartile CalculatorFind Q1, median, Q3, the interquartile range, and Tukey-fence outliers in any list, as a five-number summary. 50 in 2,3,3,4,4,4,5,5,6,50 is an outlier.Random Number GeneratorGenerate whole numbers or decimals in a range, with a seed so results are reproducible and shareable. Not secure, so never use for passwords or lotteries.Ratio CalculatorSimplify a ratio to lowest terms, solve a proportion a:b = c:x for the missing term, or scale a ratio by a factor. Includes the decimal equivalent.Roman Numeral ConverterConvert numbers to Roman numerals and back, with strict validation that rejects non-canonical forms like IIII or IC. 1994 = MCMXCIV, 2026 = MMXXVI.Root CalculatorFind the nth root of any number, including square roots, cube roots, and odd roots of negative numbers. The cube root of -8 is -2, since -2 cubed equals -8.Rounding CalculatorRound a number by decimal places, significant figures, or nearest multiple, and compare all six rules: half up, half down, half to even, ceiling, floor.Sample Size CalculatorFind the survey sample size needed for a confidence level and margin of error using Cochran's formula, with finite population correction and a reverse mode.Scientific CalculatorType a math expression for an evaluated result, with trig in degrees or radians, logs, roots, powers, and factorials, plus the parsed expression echoed back.Scientific Notation ConverterConvert any decimal number to normalized scientific notation, or a mantissa and exponent back to a decimal. 123,400 converts exactly to 1.234 × 10^5.Sequence CalculatorFind the nth term and sum of an arithmetic or geometric sequence. Includes the sum to infinity for geometric series when the common ratio is between -1 and 1.Slope CalculatorFind the slope between two points, the line equation y = mx + b, the distance and midpoint, and the angle from horizontal. Handles vertical lines correctly.Standard Deviation CalculatorCalculate sample standard deviation (n − 1) and population standard deviation (n) from a list of numbers, plus variance and mean for both.Surface Area CalculatorFind the surface area and volume of a box, cube, cylinder, sphere, cone, pyramid, or triangular prism, with exact formulas and derived slant heights.Triangle CalculatorSolve a triangle from SSS, SAS, ASA, or SSA input. Get every side, angle, area, and type, with the SSA ambiguous case (zero, one, two solutions) handled.Unit Circle CalculatorFind sin, cos and tan for any angle in degrees or radians, its (x, y) coordinate, quadrant and reference angle, plus the 16 standard unit-circle angles.Volume CalculatorCalculate volume for a box, cylinder, sphere, or cone using the standard geometric formulas. A unit sphere (radius 1) returns exactly 4.18879 cubic units.Weighted Average CalculatorCalculate a weighted average from two lists of values and weights, such as exam scores weighted by category. Weights don't need to add up to 1 or 100.Z-Score CalculatorCalculate a z-score from a value, mean, and standard deviation, plus its percentile and two-tail p-value. A z-score of 1.96 sits at the 97.5th percentile.