Math Calculators

From everyday percentages to standard deviation, factor problems and geometry, these math calculators show the formula behind every answer so you can check your work and learn as you go.

Percentage Calculator

Free percentage calculator: find what X% of a number is, what percent one number is of another, or increase a number by a percent.

Percentage Increase Calculator

Calculate percentage increase between two values instantly.

Percentage Decrease Calculator

Calculate percentage decrease between two values instantly.

Percentage Difference Calculator

Find the percentage difference between two values using their average as the reference.

Percentage Change Calculator

Calculate percentage change from an old value to a new value.

Percentage Off Calculator

Find the sale price after a percentage discount and how much you save.

Tank Volume Calculator

Calculate the capacity of a cylindrical, rectangular or spherical tank in gallons, liters and cubic feet from its dimensions in inches.

Standard Deviation Calculator

Calculate standard deviation (population and sample), variance and mean for any data set.

Mean Calculator

Find the mean (average) of any list of numbers, plus the sum, count, minimum, maximum and range.

Mean Median Mode Calculator

Calculate mean, median, mode and range for any data set in one step.

Percentile Calculator

Find the value at a given percentile (like the 75th or 90th) in your data set using the standard linear-interpolation method used by Excel and NumPy.

Covariance Calculator

Calculate sample and population covariance between two data sets, plus the Pearson correlation coefficient.

Factor Calculator

Find every factor of a number, its prime factorization, and whether it is prime.

Factoring Calculator

Factor a quadratic expression ax² + bx + c into two binomials and see its roots and discriminant.

Simplify Calculator

Simplify any fraction to lowest terms instantly.

Radical Calculator

Simplify square roots to simplest radical form (like 6√2) with the decimal approximation, or evaluate any nth root.

Rounding Calculator

Round any number to the nearest integer, tenth, hundredth, thousand, or a custom number of decimal places.

Quadratic Formula Calculator

Solve any quadratic equation with the quadratic formula.

RREF Calculator

Compute the reduced row echelon form (RREF) of a matrix with Gauss–Jordan elimination, plus its rank.

Linear Regression Calculator

Fit a least-squares regression line to paired data.

P-Value Calculator

Convert a z-score or t-statistic into a p-value for left, right or two-tailed tests.

Circle Calculator

Enter any one value — radius, diameter, circumference or area — and get all four circle measurements instantly, using full-precision π.

Circumference Calculator

Find a circle’s circumference from its radius, diameter or area, and get the remaining measurements too.

Surface Area Calculator

Calculate the surface area of a cube, rectangular prism, cylinder, sphere or cone from its dimensions.

Arc Length Calculator

Find arc length, sector area and chord length from a circle’s radius and central angle in degrees.

Triangle Area Calculator

Calculate a triangle’s area three ways: base × height, Heron’s formula from three sides, or two sides with the included angle.

Right Triangle Calculator

Solve a right triangle from two legs, or from one leg and the hypotenuse.

Special Right Triangle Calculator

Solve 45°-45°-90° and 30°-60°-90° triangles from any single side using their fixed side ratios.

Volume of a Cone Calculator

Calculate a cone’s volume from radius and height, plus slant height, lateral area and total surface area.

Solve for X Calculator

Solve a one-step or two-step linear equation ax + b = c for x.

Inequality Calculator

Solve a linear inequality for x, with the sign-flip rule for negative coefficients handled automatically.

Fraction Calculator

Add, subtract, multiply or divide two fractions and get the result in lowest terms, plus its decimal and mixed-number forms.

Long Division Calculator

Divide any two numbers and get the quotient, the remainder and the full decimal result.

Average Percentage Calculator

Average a list of percentages instantly, with the median, sum and count.