Math Calculators

18 free tools, grouped by topic.

Statistics

Average CalculatorCalculate the average (mean) of a list of numbers, plus the count, sum, minimum, maximum, and range. Paste values separated by commas, spaces, or lines.
Confidence Interval CalculatorCalculate a confidence interval for a mean or a proportion. Enter your sample stats and confidence level for the margin of error and bounds.
Linear Regression CalculatorFit a least-squares line to x and y data. Get the slope, intercept, correlation r, r-squared, and a prediction.
Mean Median Mode CalculatorCalculate the mean, median, mode, range, and sum of a list of numbers. Fast and private.
Standard Deviation CalculatorFind population and sample standard deviation, variance, and mean for a list of numbers. Fast and private.

Circle CalculatorFind a circle radius, diameter, circumference, and area from any one known value. Fast and private.
Pythagorean Theorem CalculatorFind the hypotenuse from two legs, or a missing leg from the hypotenuse, using a squared plus b squared equals c squared.
Right Triangle CalculatorSolve a right triangle from two sides. Get the hypotenuse or missing leg, both acute angles, and the area.
Slope CalculatorCalculate the slope and y-intercept of a line from two points, for y = mx + b. Fast and private.

Decimal to Fraction ConverterConvert a decimal number to a reduced fraction, shown as an improper fraction and a mixed number.
Fraction to Decimal ConverterConvert a fraction to its decimal value by dividing the numerator by the denominator.
Percentage CalculatorFree percentage calculator for three questions: what is X% of Y, X is what percent of Y, and the percent change from one value to another.
Percentage Change CalculatorCalculate the percentage increase or decrease between two numbers, with the raw difference. Fast and private.
Percentage Increase CalculatorCalculate the percentage increase between two numbers. Enter the old and new values to get the percent change and the difference.
Quadratic Formula CalculatorSolve ax^2 + bx + c = 0 with the quadratic formula. Get real or complex roots, the discriminant, and the vertex.
Ratio CalculatorSimplify a ratio to lowest terms or solve a proportion for a missing term. Handles A:B and A:B = C:x.

Probability CalculatorCalculate the combined probability of two independent events: both, either, neither, and one but not the other, from each event probability.
Z-Score CalculatorCalculate a z-score from a value, mean, and standard deviation, plus the percentile and two-tailed p-value from the standard normal distribution.