Math calculators
A lot of everyday math comes back to a few moves: scaling by a percentage, comparing two quantities, solving for an unknown, or measuring a shape. These calculators do the arithmetic and print the method alongside the answer, so you can follow the reasoning instead of taking the number on trust.
Each tool also says where its method breaks down, for example why a percentage change from zero has no answer, or why three lengths only form a triangle when any two of them add up to more than the third.
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- Basic CalculatorA free online calculator to add, subtract, multiply and divide, with brackets, a percent key and the working shown for every answer.
- Equation SolverSolve an equation with one unknown, such as 3(x − 2) + 4 = 2x + 7, with every step shown: multiply out, gather terms, get x alone and check.
- Fraction CalculatorAdd, subtract, multiply or divide two fractions or mixed numbers. Get the answer in simplest form, as a mixed number, a decimal and a percent.
- Graphing CalculatorDraw up to four graphs, then zoom and trace them. Find where a graph crosses zero, where two graphs meet, and its lowest or highest point.
- Percentage CalculatorFind a percentage of a number, what percent one number is of another, the whole from a part, or the percent change between two numbers.
- Percentage Change CalculatorMeasure the percent increase or decrease between two values, raise or lower a value by a percent, or find the original value before a change.
- Pythagorean Theorem CalculatorFind the missing side of a right triangle from the other two, in decimal and exact radical form, or check whether three sides make a right triangle.
- Quadratic Equation CalculatorSolve ax² + bx + c = 0 and see every step. Get real or complex roots as exact answers and decimals, plus the factored and vertex forms.
- Scientific CalculatorA free scientific calculator with sin, cos, tan, logs, powers, roots, factorials and memory, that shows how it worked out every answer.
- Square Root CalculatorFind the square root, cube root or any nth root of a number, with the simplified radical form, imaginary square roots of negatives and full working.
- Area CalculatorFind how much surface a rectangle, square, circle, triangle, trapezoid, parallelogram or ellipse covers, in square meters, square feet and acres.
- Circle CalculatorKnow one measurement of a circle? Enter its radius, diameter, circumference or area and get the other three.
- Exponent CalculatorRaise a number to any power, including negative, decimal and fraction exponents. Or work backward to find a missing exponent, with every step shown.
- GCF CalculatorFind the greatest common factor of 2 to 10 whole numbers, with the Euclidean algorithm worked out.
- LCM CalculatorFind the least common multiple (the smallest number they all divide into) of 2 to 10 whole numbers, with each step shown.
- Logarithm CalculatorFind the logarithm of a number in base 10, base e, base 2 or any custom base, with the change-of-base step shown.
- Long Division CalculatorWork through long division one step at a time, and get an answer with a remainder or a decimal with any repeating digits marked.
- Matrix CalculatorFind the determinant, inverse or transpose of a 2×2 or 3×3 matrix, or add, subtract, multiply and scale matrices, with the working shown.
- Number Base ConverterConvert whole numbers between binary, octal, decimal, hex and any base from 2 to 36. Long numbers stay exact, and an optional two's complement view shows how a computer stores them.
- Ratio CalculatorFind the missing number when two ratios are equal, or simplify a ratio to the smallest whole numbers that mean the same thing.
- Roman Numeral ConverterConvert numbers from 1 to 3999 into Roman numerals and back, with strict checking of standard modern form.
- Rounding CalculatorRound a number to a set number of decimal places, significant figures or the nearest 5, 10 or quarter, and compare four rounding rules side by side.
- Scientific Notation CalculatorConvert numbers to scientific, E and engineering notation with a chosen number of significant figures, or expand them back to decimals.
- Significant Figures CalculatorCount the significant figures in a number exactly as written, and round it to any number of significant figures.
- Simplify Fractions CalculatorShrink a fraction to its simplest form with every step shown, see fractions that are worth the same, and check whether two fractions are equal.
- Slope CalculatorFind the slope, line equation, y-intercept, distance, angle and midpoint for two points.
- Triangle Solver CalculatorKnow three sides or angles of a triangle (SSS, SAS, ASA, AAS or SSA)? Find all the rest with the laws of sines and cosines.
- Volume CalculatorFind the volume of a box, cube, cylinder, sphere, cone or rectangular pyramid, with liters, US gallons, cubic meters and cubic feet.
- Angle of Elevation CalculatorSolve angle of elevation and depression problems: find a height, a distance or the angle, allow for eye height, or find a height from two sightings.
- Arc Length CalculatorFind the length of a circular arc from the radius and central angle, chord or sector area, plus the sector's area and perimeter.
- Arithmetic Sequence CalculatorFind any term of an arithmetic sequence and the sum of its first n terms. Or find where a given value sits, from the first term and the step size.
- Cartesian to Polar ConverterConvert a point between Cartesian coordinates (x, y) and polar coordinates (r, θ) in either direction, with the angle in degrees and radians.
- Completing the Square CalculatorRewrite ax² + bx + c as a(x − h)² + k and solve the equation by completing the square, with every step shown in plain words.
- Complex Number CalculatorDo math with complex numbers (a + bi): add, subtract, multiply, divide, powers and roots, and switch between rectangular and polar form.
- Cubic Equation CalculatorFind all three answers (roots) of a cubic equation, ax³ + bx² + cx + d = 0, real or complex, with every step shown.
- Definite Integral CalculatorFind the area under a curve between two x-values. Uses adaptive Gauss–Kronrod quadrature, gives an error estimate and checks the answer with Simpson's rule.
- Derivative CalculatorFind the derivative of a function written in x, with the rule used at every step, then get the slope and the tangent line at any point.
- Distance Between Points CalculatorFind the straight-line distance between two points in 2D or 3D, as a decimal and in exact square-root form. Get the grid distance, midpoint and slope too.
- Ellipse CalculatorEnter an oval's half-width and half-height to get its area, exact perimeter, how stretched it is, its key points and its equation.
- Exponential Growth and Decay CalculatorModel an amount that grows or shrinks by a steady percent or continuous rate. Find the final amount, the time to reach a target, or the rate itself.
- Factorial CalculatorGet the exact factorial (n!) of any whole number up to 3,000, plus how many digits it has and how many zeros it ends in.
- Factors CalculatorSee every number that divides evenly into a whole number, paired up, with how many there are and what they add up to.
- Fraction and Decimal ConverterTurn a decimal, including a repeating one, into an exact fraction, or turn a fraction into its exact decimal with the repeating block marked.
- Geometric Sequence CalculatorFind the nth term and partial sum of a geometric sequence from its first term and common ratio, plus the infinite sum when it exists.
- Hexagon CalculatorEnter any one measurement of a regular hexagon (side, perimeter, area, diagonal or radius) and get all the others.
- Inequality SolverSolve a linear or quadratic inequality in x exactly. Get the answer in interval notation, with every step shown, from rearranging to testing signs.
- Linear Interpolation CalculatorEstimate a value between two known points on a straight line, extend the line past them, or work backwards from a y value to its x.
- Midpoint CalculatorFind the point halfway between two points, a missing endpoint from the midpoint, or the point that splits a segment in any ratio, in 2D or 3D.
- Mixed Number ConverterTurn a mixed number such as 2 3/4 into a single (improper) fraction, or back again, including negatives, with the working shown.
- Modulo CalculatorFind a mod n, the remainder after division, with its quotient. Choose the truncated, floored or Euclidean rule for negative numbers.
- Parabola CalculatorGet a parabola's turning point (vertex), focus, directrix, axis, vertex form and intercepts. Or build its equation from a focus and directrix.
- Percent Error CalculatorSee how far your measurement is from the true or accepted value, as a percent. Show it with or without a plus or minus sign.
- Perimeter CalculatorFind the distance around a rectangle, square, triangle, parallelogram, trapezoid, regular polygon, circle, semicircle or any polygon from its sides or corner points.
- Polynomial Factoring CalculatorBreak a polynomial into its simplest factors and find its roots exactly, using common factors, the rational root test and synthetic division, with every step shown.
- Prime Factorization CalculatorBreak a whole number up to 10^15 into prime factors with exponents, with every division shown.
- Prime Number CalculatorCheck whether a whole number up to 2^64 is prime, and find its smallest factor and the primes just above and below it.
- Proportion CalculatorSolve a proportion A/B = C/D for whichever value is missing, using cross-multiplication with every step shown.
- Regular Polygon CalculatorFind the area, perimeter, apothem, circumradius, angles and diagonals of any regular polygon from its number of sides and one known measurement.
- Right Triangle CalculatorSolve a right triangle from any two known values, such as a side and an angle, two sides, the area or the height. Get every side, angle and measurement.
- Similar Triangles CalculatorFind the missing sides of a similar triangle from one matching side, scale a triangle by a factor, or check whether two triangles are similar.
- Sphere CalculatorKnow one measurement of a ball or sphere? Enter its radius, diameter, circumference, surface area or volume to get the other four.
- Surface Area CalculatorFind the total, side (lateral) and base surface area of a cube, box, cylinder, sphere, cone or rectangular pyramid, in your choice of units.
- System of Equations CalculatorSolve two or three linear equations together, exactly, by Gauss–Jordan elimination or Cramer's rule, and find out when there is no solution or infinitely many.
- Trigonometry CalculatorFind the sine, cosine, tangent, cosecant, secant and cotangent of an angle. Or work back from a value to the angle with arcsin, arccos and arctan.
- Vector CalculatorWork with vectors in 2D or 3D. Find a length, a direction, a sum or difference, the dot product, the angle between two vectors or the cross product.