Math

Percentages and everyday math.

Percentage

Percentage CalculatorX% of Y, X as a percent of Y, percentage change and percentage difference.Percent Error CalculatorCompare an observed value with an exact value.

Average

Average CalculatorMean of a list of numbers plus sum and count.

Statistics

Mean, Median, Mode, Range CalculatorDescriptive statistics for a data set.Standard Deviation Calculatorσ and variance for a sample or population.Z-score CalculatorStandardize a value and read its probability.Confidence Interval CalculatorCI for a proportion or a sample mean.Sample Size CalculatorHow many responses do you need?P-value CalculatorOne- and two-tailed p-values from a z-score.Linear Regression CalculatorSlope, intercept, r and r² — with the scatter and fit line, live.

Numbers

Rounding CalculatorRound to a decimal place or to significant figures.Scientific Notation CalculatorConvert between decimal and scientific notation.Base ConverterConvert numbers between any bases 2–36.Big Number CalculatorExact arithmetic for arbitrarily large integers.

Counting

Permutation and Combination CalculatorCount ordered arrangements (nPr) and unordered selections (nCr).Probability CalculatorSingle-event and two-independent-event probability.

Scientific

Scientific CalculatorExpressions, trig, logs and factorials — live, with history.

Fractions

Fraction CalculatorAdd, subtract, multiply and divide fractions.

Ratios

Ratio CalculatorSimplify, scale and solve ratios.

Powers & logs

Exponent CalculatorEvaluate powers with real exponents.Root CalculatorSquare, cube and nth roots.Log CalculatorLogarithms in any base.

Algebra

Quadratic Formula CalculatorSolve ax² + bx + c = 0.

Lines

Slope CalculatorSlope, intercept and line equation from two points.Distance CalculatorDistance and midpoint between two points.

Sequences

Number Sequence CalculatorDetect the pattern and predict the next terms.

Growth & decay

Half-life CalculatorRadioactive decay and half-life problems.

Circle

Circle CalculatorRadius, diameter, circumference and area of a circle.

Triangles

Pythagorean Theorem Calculatora² + b² = c² for right triangles.Right Triangle CalculatorSolve right triangles from two known values.Triangle CalculatorSolve any triangle from SSS, SAS or ASA.

Measurement

Area CalculatorArea of rectangles, triangles, circles and more.Volume CalculatorVolume of boxes, spheres, cylinders, cones and more.Surface Area CalculatorSurface area of common 3D solids.

Trigonometry

Trigonometry CalculatorAll six functions for any angle — on the unit circle, live.

Number theory

Greatest Common Factor CalculatorGCF / GCD of two or more numbers.Least Common Multiple CalculatorLCM of two or more numbers.Factor CalculatorFind every factor pair of an integer.Prime Factorization CalculatorBreak any integer into its prime factors.