Math · Calculators
28 tools in this section, each with a documented method and sources.
Random number generatorTier 0Pick a range and get truly unpredictable numbers for draws, games, samples and decisions.PercentageTier 0Three everyday percentage questions in one place: a percent of a number, one number as a percent of another, and the percent change from one value to another.Average calculatorTier 0Paste a list of numbers and get every common average at once.Fraction calculatorTier 0Type two fractions, mixed numbers or decimals and pick an operation.Square rootTier 0Enter a number and the root you want; whole numbers also get their simplified radical form.Circle areaTier 0Enter the radius, diameter, circumference or area to get all the others.Quadratic equation solverTier 0Enter a, b and c to find where the parabola crosses zero.Ratio calculatorTier 0Enter a ratio and a new value to scale it, and see the ratio in its simplest form.Standard deviationTier 0Paste your data to see how spread out it is, using the right formula for samples or whole populations.Pythagorean theoremTier 0Enter two sides of a right triangle to find the third.Triangle areaTier 0Use base and height, or enter all three sides when you don't know the height.Decimal to fractionTier 0Type a decimal and get the simplest fraction, or the nearest one with a denominator you can measure.Exponent calculatorTier 0Enter a base and an exponent to get the power.Scientific notationTier 0Write very large or very small numbers compactly, the way scientists and engineers do.Slope calculatorTier 0Enter two points to get the slope and the line through them.Cylinder volumeTier 0Enter the radius and height to get the volume and surface areas.Rectangle areaTier 0Enter length and width to get the area, the perimeter and the diagonal.GCF and LCMTier 0Enter two or more whole numbers to get their GCF and LCM.Rounding calculatorTier 0Type a number and choose how to round it; the digits you type are rounded exactly.Box volumeTier 0Enter length, width and height to get the volume and surface area.Logarithm calculatorTier 0Find the power a base must be raised to in order to give your number.Percent errorTier 0Compare an experimental result with the accepted value.Permutations and combinationsTier 0Count how many ways you can choose r items from n, when order matters and when it does not.Sphere volumeTier 0Enter the radius to get the volume, surface area and diameter.Trapezoid areaTier 0Enter both parallel sides and the height between them.Prime factorizationTier 0Enter a whole number to break it down into prime factors.Cone volumeTier 0Enter the base radius and the height.FactorialTier 0Enter n to get n! = 1 × 2 × … × n, exactly.