Math calculators
Percentages, ratios, area, volume, GCD-LCM, standard deviation and unit conversions.
Area CalculatorFind the area of a square, rectangle, triangle, circle, trapezoid, ellipse or polygon, with the formula shown and the result in m², cm² and hectares.Combination Calculator C(n, r)Calculate C(n, r) exactly: combinations with and without repetition, the worked formula, the probability and a table of every k.Compound Interest CalculatorCalculate compound interest yearly, monthly, daily or continuously: future value, effective rate, the rule of 72 and a year-by-year table.Exponent CalculatorRaise a number to any power: aⁿ, negative and fractional exponents, scientific notation and exact large results, with the exponent rules.Factorial Calculator (n!)Calculate n factorial: the exact value up to 10,000!, digit count, trailing zeros, scientific notation and Stirling’s approximation, with a step-by-step table.GCD and LCM CalculatorCalculate the GCD and LCM of 2 to 10 numbers with the division ladder, Euclid’s algorithm, prime factors and the GCD × LCM = a × b check.Golden Ratio Calculator (φ)Split a length into its golden-ratio long and short parts, or find the rest from one part; the 61.8% / 38.2% shares and the Fibonacci ratios closing in on φ.Inches to Centimetres ConverterConvert inches to centimetres and back, feet and inches to cm, and cm to feet and inches. Quick for screen sizes and heights.Miles to Kilometres ConverterConvert miles to kilometres and back, see how a nautical mile differs from a mile, and convert mph, knots, km/h and m/s.Modulo CalculatorModulo calculator: remainders of negative numbers, (a + b) mod n, (a × b) mod n, aᵉ mod n by repeated squaring and the modular inverse by the extended Euclidean algorithm.Number Base ConverterConvert between binary, octal, decimal and hexadecimal, or any base from 2 to 36, with fractions, step-by-step division and a place-value table.Number to Words ConverterTurn figures into words: the amount in words for Turkish cheques and invoices, decimals, ordinals and the English reading, up to one quadrillion.Pascal’s TriangleBuild Pascal’s triangle up to row 30 with the expansion of (a + b)ⁿ, the binomial coefficients C(n, k), the row sum 2ⁿ and the Fibonacci diagonals.Percentage CalculatorWork out a percentage of a number, what percent one is of another, percentage increase and decrease, and the price before a discount.Perimeter CalculatorWork out the perimeter of a square, rectangle, triangle, circle, trapezoid, ellipse or polygon, with the formula and the result in mm, cm, m, km and feet.Permutation Calculator P(n, r)Permutations P(n, r), arrangements with repetition (nʳ), anagrams of words with repeated letters and circular permutations, with the worked formula and exact result.Prime Factorisation CalculatorSplit a number into its prime factors: index form, step-by-step division, a prime check, the number and sum of divisors and the list of divisors.Random Number GeneratorGenerate random numbers in any range: draws without repeats, sorting, dice rolls and coin flips, seeded by the browser’s cryptographic generator.Ratio and Proportion CalculatorSolve direct and inverse proportions, simplify a ratio, or split an amount in a ratio such as 2:3:5, with a step-by-step rule of three.Root Calculator: Square, Cube and n-th RootsFind square, cube and n-th roots, check whether a root is exact and simplify radicals (√72 = 6√2, ∛54 = 3∛2) step by step.Simple Interest CalculatorWork out simple interest and the total with I = P × r × t, over days, months or years, with a 360- or 365-day year.Square Metre, Dunam and Hectare ConverterConvert square metres to dunams, hectares, decares, acres and square feet, and back. See every land-area unit in one table.Standard Deviation CalculatorSample and population standard deviation, variance, mean, median, mode, interquartile range and coefficient of variation, with a step-by-step deviation table.Volume CalculatorCalculate the volume of a cube, box, cylinder, sphere, cone or pyramid with the formula shown, plus litres, m³, gallons and the surface area.