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2x2 Matrix Determinant CalculatorCalculate the determinant of a 2×2 matrix from its four entries.2x2 Matrix Multiplication CalculatorMultiply two 2×2 matrices together to find the resulting 2×2 matrix.3D Distance CalculatorCalculate the straight-line distance between two points in 3D space.3D Vector Dot Product CalculatorCalculate the dot product of two 3D vectors from their x, y and z components.Absolute Value CalculatorCalculate the absolute value of a number — its magnitude, ignoring sign.Annulus (Ring) Area CalculatorCalculate the area of an annulus (ring shape) — the area between two concentric circles.Arithmetic Sequence CalculatorFinds the nth term and the sum of the first n terms of an arithmetic sequence.Average Calculator (5 Numbers)Calculate the average (arithmetic mean) of up to five numbers.Average Speed for a Round Trip CalculatorCalculate the correct average speed for a round trip where you travel the same distance at two different speeds each way.Ceiling CalculatorCalculate the ceiling of a number — the smallest whole number greater than or equal to it.Circle Area and Circumference CalculatorCalculate the area, circumference and diameter of a circle from its radius.Coefficient of Variation CalculatorCalculate the coefficient of variation (CV) — a standardized measure of relative variability, expressed as a percentage of the mean.Compound Percentage Change CalculatorApplies two sequential percentage changes to a starting value and reports the combined effect.Confidence Interval Calculator (for a Mean)Calculate a confidence interval around a sample mean at a chosen confidence level.Cube and Square Root CalculatorCalculates the square, square root, cube and cube root of a number in one step.Cube Volume and Surface Area CalculatorCalculate the volume, total surface area and space (interior) diagonal of a cube from its side length.Cylinder Surface Area CalculatorCalculate the total surface area of a cylinder from its radius and height.Distance Between Two Points CalculatorCalculates the straight-line distance between two points on a coordinate plane.Distance, Speed and Time CalculatorSolve for speed, time or distance using the classic Distance = Speed × Time relationship — enter any two values to find the third.Ellipse Area CalculatorCalculate the area of an ellipse from its semi-major and semi-minor axis lengths.Ellipse Perimeter Calculator (Ramanujan Approximation)Estimate an ellipse's perimeter using Ramanujan's highly accurate approximation formula (there is no exact elementary formula for an ellipse's perimeter).Exponent (Power) CalculatorCalculate the result of raising a base number to an exponent, including fractional and negative exponents.Exponential Growth and Decay CalculatorModel exponential growth or decay: project how a starting value changes over a number of periods at a fixed percentage rate per period.Floor CalculatorCalculate the floor of a number — the largest whole number less than or equal to it.Fraction Addition and Subtraction CalculatorAdd or subtract two fractions and see the result as an unreduced fraction and a decimal.Fraction Multiplication and Division CalculatorMultiply or divide two fractions and see the result as an unreduced fraction and a decimal.Fraction to Decimal CalculatorConvert a fraction into its decimal equivalent by dividing the numerator by the denominator.Fraction to Percentage CalculatorConvert a fraction into a percentage and decimal value.Geometric Sequence CalculatorFinds the nth term and the sum of the first n terms of a geometric sequence.Hemisphere Volume and Surface Area CalculatorCalculate the volume, curved surface area and total surface area of a hemisphere.Heron's Formula Triangle Area CalculatorCalculate a triangle's area from its three side lengths using Heron's Formula, with an automatic check that the three sides can actually form a valid triangle.Linear Equation Solver (ax + b = c)Solve a simple linear equation of the form ax + b = c for the value of x.Margin of Error CalculatorCalculate the margin of error for a sample mean at a chosen confidence level.Mean Calculator (Choose 2 to 10 Numbers)Calculate the mean (average) of anywhere from 2 to 10 numbers by first choosing how many values you want to enter.Median of Three Numbers CalculatorFinds the middle value (median) of three numbers without needing to sort them by hand.Midpoint CalculatorFind the midpoint (the point exactly halfway) between two coordinates on a 2D plane.Mixed Number to Improper Fraction CalculatorConvert a mixed number like 2 3/4 into an improper fraction and its decimal equivalent.Mode Calculator (5 Numbers)Calculate the mode (most frequently occurring value) among 5 numbers.Modulo CalculatorCalculate the modulo (remainder after division) of two numbers.Parallelogram Area and Perimeter CalculatorCalculate the area and perimeter of a parallelogram from its base, height and side length.Per Capita CalculatorCalculate a per-capita figure by dividing a total value (like GDP, spending, or emissions) by a population count.Percentage Change CalculatorCalculate the percentage increase or decrease between two values.Percentage Difference CalculatorCalculate the percentage difference between two numbers, using their average as the base (unlike percentage change, which uses the original value as the base).Percentage Error CalculatorCalculate the percentage error between a measured or experimental value and the true or accepted value — commonly used in science and lab experiments.Percentage of a Number CalculatorFinds what a given percentage of a number equals.Percentage Point Difference CalculatorCalculate the difference between two percentages in percentage points, and separately the relative percentage change — two figures that are often confused.Proportion CalculatorSolve a proportion of the form A/B = C/D for the missing value, given the other three.Pyramid Volume CalculatorCalculate the volume of a pyramid (of any base shape) from its base area and height.Quadratic Formula CalculatorSolves ax² + bx + c = 0 for its real roots, discriminant and root type.Quadratic Vertex Form CalculatorFind the vertex, axis of symmetry, and direction of opening of a quadratic function.Rectangle Perimeter and Area CalculatorCalculate the area and perimeter of a rectangle from its length and width.Rectangular Prism Diagonal CalculatorCalculate the space diagonal (corner-to-corner distance) of a rectangular box.Reverse Percentage CalculatorWork backwards from a final value and a known percentage change to find the original value it started from.Rhombus Area Calculator (Diagonals Method)Calculate the area of a rhombus from the lengths of its two diagonals.Right Triangle Calculator (Pythagorean Theorem)Calculate the hypotenuse, area and perimeter of a right triangle from its two legs.Rounding CalculatorRound a number to a chosen number of decimal places using standard round-half-up rounding.Rule of Three CalculatorSolve a rule-of-three (direct proportion) problem: if A corresponds to B, find what C corresponds to.Sample Size Calculator (for Estimating a Mean)Calculate the minimum sample size needed to estimate a mean within a desired margin of error at a chosen confidence level.Sector Area CalculatorCalculate the area and arc length of a circular sector (a 'pie slice' of a circle) given its radius and angle.Simple Probability CalculatorCalculates the probability and odds of a favorable outcome from the total number of possible outcomes.Slope of a Line CalculatorFinds the slope and y-intercept of the line through two given points.Sphere Volume and Surface Area CalculatorCalculate the volume and surface area of a sphere from its radius.Square Perimeter and Area CalculatorCalculate the area, perimeter and diagonal length of a square from its side length.Standard Deviation Calculator (5 Numbers)Calculate the mean, variance and population standard deviation of five numbers.Standard Error of the Mean CalculatorCalculate the standard error of the mean — how much a sample mean is expected to vary from the true population mean.Trapezoid Area CalculatorCalculate the area of a trapezoid from its two parallel side lengths and height.Triangle Area Calculator (Base and Height)Calculate the area of a triangle from its base and perpendicular height.Vector Cross Product Calculator (3D)Calculate the cross product of two 3D vectors, producing a new vector perpendicular to both.Vector Magnitude Calculator (3D)Calculate the magnitude (length) of a 3D or 2D vector from its components.Volume of a Cone CalculatorCalculate the volume and base area of a cone from its radius and height.Weighted Average CalculatorCalculate a weighted average from up to three values and their weights.What Percent Is X of Y CalculatorCalculate what percent one number is of another (e.g. 25 is what percent of 200?).Z-Score CalculatorCalculate a z-score (standard score) from a value, mean, and standard deviation.
