Math
Percentages, fractions, statistics, and geometry.
59 calculators
Area Calculator — square, rectangle, triangle, circleFind the area of a square (a²), rectangle (a×b), triangle (½ base × height) or circle (πr²). Pick a shape and enter its dimensions.Arithmetic Sequence Calculator — nth term and sumFind the nth term and the sum of an arithmetic sequence from the first term and common difference. For a₁=2, d=3, the 10th term is 29 and the first 10 terms sum to 155.Average Calculator — arithmetic, geometric & harmonic meanFind the average of a list of numbers — the arithmetic mean, geometric mean, harmonic mean and median. Enter numbers separated by commas or spaces. For 2, 4, 4, 4, 5, 5, 7, 9 the arithmetic mean is 5.Binomial Distribution Calculator — probability of k successes in n trialsFind the probability of exactly k successes in n independent trials with success probability p: P = C(n,k) × p^k × (1−p)^(n−k). Enter n, k and p.Calculator — free online basic calculatorA free online basic calculator for everyday arithmetic. Add, subtract, multiply, and divide with memory keys, following the standard order of operations (2 + 3 × 4 = 14).Circle Calculator — area, circumference and diameter from radiusFrom a circle's radius, find its area (πr²), circumference (2πr) and diameter (2r). Enter the radius — for r = 5, area ≈ 78.54 and circumference ≈ 31.42.Confidence Interval Calculator — for a mean (z-interval)Find the confidence interval for a mean: x̄ ± z·σ/√n. Enter the sample mean, standard deviation and size, pick 90/95/99%, and read the margin of error and bounds.Cube Root Calculator — find ∛xFind the cube root of a number, ∛x — the value whose cube equals x. Works for negatives too: ∛27 = 3 and ∛−8 = −2. Every real number has one real cube root.Decimal to Fraction Calculator — convert a decimal to a fractionConvert any decimal to a fraction in lowest terms and a mixed number. Enter a decimal to see its exact fraction. 0.75 is 3/4; 2.75 is 11/4, or 2 3/4.Descriptive Statistics Calculator — full data summaryGet a complete descriptive-statistics summary of a data set: count, sum, mean, median, mode, minimum, maximum, range, variance and standard deviation. Enter numbers separated by commas or spaces.Distance Calculator — distance between two pointsFind the straight-line distance between two points with the distance formula: d = √((x2 − x1)² + (y2 − y1)²), the Pythagorean theorem in coordinates.Exponent Calculator — raise a base to a powerCompute a base raised to an exponent, base^n — including negative exponents (reciprocals) and fractional exponents (roots). Enter a base and a power.Factorial Calculator — compute n! for any whole numberCompute the factorial n! = 1 × 2 × 3 × ... × n, the product of all positive integers up to n, with 0! = 1. Enter a whole number to get its factorial.Fraction Calculator — add, subtract, multiply, divide fractionsAdd, subtract, multiply or divide two fractions and get the answer in lowest terms, as a mixed number and as a decimal. 1/2 + 1/3 = 5/6.Fraction to Decimal Calculator — convert a fraction to a decimalConvert a fraction to a decimal by dividing the numerator by the denominator: a/b = a ÷ b. Enter a numerator and denominator, like 3/4 = 0.75.Fraction to Percent Calculator — convert a fraction to a percentageConvert any fraction to a percentage and a decimal. Enter a numerator and denominator to see the percent. 3/4 is 75%; 1/3 is about 33.33%.GCF Calculator — greatest common factor of two numbersFind the greatest common factor (GCF), also called the greatest common divisor, of two whole numbers — the largest number that divides both exactly.GPA Calculator — grade point averageCalculate your GPA from letter grades and credit hours. GPA is the credit-weighted average of grade points on the 4.0 scale. For B (3 credits), A- (4), C (2) and C (3) the GPA is about 2.81.Hex / Decimal / Binary Converter — number base converterConvert a decimal number to binary, octal and hexadecimal. Enter a whole number to see all three bases. 255 is FF in hex, 377 in octal and 11111111 in binary.LCM Calculator — least common multiple of two numbersFind the least common multiple (LCM) of two whole numbers — the smallest number both divide into — computed as their product divided by the greatest common factor.Logarithm Calculator — log of a number to any baseCompute the logarithm of a number to any base: log_base(x) = ln(x) ÷ ln(base). It answers what power the base must be raised to to get x — log₁₀(1000) = 3.Mean, Median, Mode Calculator — measures of central tendencyFind the mean, median and mode of a list of numbers. Enter your data separated by commas or spaces. For 2, 4, 4, 4, 5, 5, 7, 9 the mean is 5, the median is 4.5 and the mode is 4.Midpoint Calculator — midpoint between two pointsFind the midpoint between two points — the point halfway between them — by averaging the coordinates: ((x1 + x2) ÷ 2, (y1 + y2) ÷ 2).Mixed Number to Fraction Calculator — convert to an improper fractionConvert a mixed number to an improper fraction and a decimal. Enter the whole number, numerator and denominator. 2 1/2 becomes 5/2, or 2.5.Modulo Calculator — remainder of a divisionFind a mod n — the remainder when one number is divided by another — plus the quotient. Enter a dividend and divisor. 17 mod 5 is 2, with a quotient of 3.Nth Root Calculator — find the nth root of a numberFind the nth root of a number, x^(1/n) — the value that raised to the power n gives x. Generalises square and cube roots: the 5th root of 32 is 2.Percent Error Calculator — measured vs true valueCalculate percent error between a measured value and the true value: |measured − actual| ÷ |actual| × 100. Enter both to get the error as a percentage.Percent to Fraction Calculator — convert a percentage to a fractionConvert any percentage to a fraction in lowest terms and a mixed number. Enter a percent to see its fraction. 75% is 3/4; 150% is 3/2, or 1 1/2.Percentage Calculator — what percent one number is of anotherWork out what percent one number is of another: percentage = part ÷ whole × 100. Enter a part and a whole to get the exact percentage, with the steps shown.Percentage Change Calculator — increase or decrease between two numbersCalculate the percentage change from one number to another: change = (new − old) ÷ old × 100. Positive is an increase, negative a decrease — steps shown.Percentage Increase Calculator — increase or decrease a number by a percentIncrease or decrease a number by a percentage: result = value × (1 + percent ÷ 100). Enter a value and a percent (negative to decrease) to get the new amount.Percentage of a Number Calculator — what is X% of YFind what a percentage of a number is: amount = percent ÷ 100 × number. Enter a percent and a number to get the result, like 15% of 80 = 12, steps shown.Perimeter Calculator — square, rectangle, triangle, circleFind the perimeter of a square (4a), rectangle (2(a+b)), triangle (a+b+c) or circle (circumference 2πr). Pick a shape and enter its dimensions.Permutation & Combination Calculator — nPr and nCrCalculate permutations (nPr, order matters) and combinations (nCr, order doesn't) of r items from n: nPr = n!/(n−r)!, nCr = n!/(r!(n−r)!). Both shown together.Prime Factorization Calculator — factor a number into primesBreak any whole number into its prime factors. Enter a number to see its prime factorization as a product of prime powers, with the count of distinct primes. 360 = 2³ × 3² × 5.Prime Number Checker — is a number prime?Check whether a whole number is prime — divisible only by 1 and itself — and if not, find its smallest prime factor. 17 is prime; 15 is composite (3 × 5).Probability Calculator — chance of an event from outcomesCalculate the probability of an event as favorable outcomes ÷ total outcomes, plus the complement (chance it doesn't happen). Enter the counts to get the odds.Proportion Calculator — solve a : b = c : xSolve a proportion a : b = c : x for the missing value by cross-multiplication: x = b × c ÷ a. Enter three terms to find the fourth.Pythagorean Theorem Calculator — hypotenuse from two legsFind the hypotenuse of a right triangle from its two legs using the Pythagorean theorem: c = √(a² + b²). Enter the two legs, like 3 and 4 giving 5.Quadratic Formula Calculator — solve ax² + bx + c = 0Solve a quadratic equation ax² + bx + c = 0 with the quadratic formula x = (−b ± √(b² − 4ac)) ÷ 2a. Enter a, b and c to get both roots and the discriminant.Range Calculator — largest minus smallestFind the range of a data set — the largest value minus the smallest — along with the minimum, maximum and midrange. Enter numbers separated by commas or spaces. For 2, 4, 4, 4, 5, 5, 7, 9 the range is 7.Ratio Calculator — simplify a ratio to lowest termsSimplify a ratio a : b to its lowest terms by dividing both sides by their greatest common divisor, and see it as a decimal. Enter two numbers to reduce.Right Triangle Calculator — hypotenuse, area, perimeter and anglesFrom the two legs of a right triangle, find the hypotenuse (√(a²+b²)), the area (½·a·b), the perimeter and the two acute angles. Enter the legs a and b.Roman Numerals Converter — number to Roman numeralConvert any whole number from 1 to 3999 into Roman numerals. Enter a number to see its numeral using I, V, X, L, C, D and M. 2026 is MMXXVI.Rounding Calculator — round to decimal places (nearest, up, down)Round a number to any number of decimal places — to the nearest (ties to even), up (ceiling) or down (floor). Enter a value, the places and the mode.Sample Size Calculator — for estimating a meanFind the minimum sample size to estimate a mean within a target margin of error: n = (z·σ/E)², rounded up. Pick 90/95/99% confidence, enter σ and the margin.Scientific Calculator — trig, logs, powers, and rootsA free online scientific calculator with sine, cosine, and tangent (and inverses), natural and base-10 logarithms, powers, roots, factorials, π and e, parentheses, and a degrees/radians switch.Scientific Notation Calculator — convert a number to a × 10ⁿConvert a number to scientific notation, a × 10ⁿ, with the mantissa between 1 and 10 and the exponent its order of magnitude. 1234 becomes 1.234 × 10³.Significant Figures Calculator — round to N sig figsRound a number to a chosen number of significant figures — the meaningful digits from the first non-zero one. 3.14159 to 3 sig figs is 3.14; 12345 to 2 is 12000.Simplify Fractions Calculator — reduce to lowest termsReduce any fraction to its lowest terms. Enter a numerator and denominator to get the simplified fraction and its decimal value. 8/12 simplifies to 2/3.Slope Calculator — slope of a line from two pointsFind the slope of a line through two points: m = (y2 − y1) ÷ (x2 − x1), the rise over the run. Positive slopes rise, negative fall, zero is horizontal.Square Root Calculator — find √xFind the square root of a number, √x — the value whose square equals x. Handles perfect squares like 144 = 12 and irrationals like √2 ≈ 1.4142.Standard Deviation Calculator — sample and populationCalculate the sample and population standard deviation and variance of a data set. Enter numbers separated by commas or spaces. For 2, 4, 4, 4, 5, 5, 7, 9 the population standard deviation is 2 and the sample standard deviation is about 2.1381.Surface Area Calculator — cube, box, sphere, cylinderFind the total surface area of a cube (6a²), box (2(ab+bc+ca)), sphere (4πr²) or cylinder (2πr(r+h)). Pick a solid and enter its dimensions.Triangle Calculator — area from three sides (Heron's formula)Find a triangle's area, perimeter and semiperimeter from its three side lengths using Heron's formula, A = √(s(s−a)(s−b)(s−c)) with s the semiperimeter.Trigonometry Calculator — sine, cosine and tangent of an angleFind the sine, cosine and tangent of an angle in degrees. For 30°, sin = 0.5, cos ≈ 0.8660 and tan ≈ 0.5774. Tangent is undefined at 90° and 270°.Variance Calculator — sample and population varianceCalculate the sample and population variance of a data set, plus the standard deviations. Enter numbers separated by commas or spaces. For 2, 4, 4, 4, 5, 5, 7, 9 the population variance is 4 and the sample variance is about 4.5714.Volume Calculator — cube, box, sphere, cylinder, coneFind the volume of a cube (a³), box (a×b×c), sphere (4/3 πr³), cylinder (πr²h) or cone (⅓ πr²h). Pick a solid and enter its dimensions.Z-Score Calculator — standard score from value, mean and SDCalculate a z-score (standard score): z = (x − mean) ÷ standard deviation. It tells you how many standard deviations a value sits above or below the mean.