All Calculators & Tools

Enter a list of numbers to calculate population and sample standard deviation.

Measure squared spread around the mean, with sample and population variance side by side.

Summarize your dataset with count, mean, median, mode, range, variance and standard deviation.

Calculate relative standard deviation as a percentage, from a dataset or a supplied mean and standard deviation.

Calculate the weighted mean of a dataset using values and their corresponding weights. Enter or paste your data, review each weighted contribution, and follow the calculation step by step.

Convert a value to a z-score, then explore standard-normal probabilities and percentiles.

Find Gaussian probabilities below, above, between or outside values, or find a value from a percentile.

Calculate exact, cumulative and tail probabilities for a fixed number of independent trials.

Find event-count probabilities from an average rate per interval, with exact, cumulative and tail modes.

Enter a custom discrete distribution to calculate expected value, variance, standard deviation and cumulative probabilities.

Calculate probabilities and critical values for Student's t-distribution using degrees of freedom and a t-value or probability.

Plan an analyzable sample size or evaluate the power of a planned study using a specific test, anticipated effect and significance level.

Calculate the probability of when the first success occurs in repeated independent trials. Choose whether to count trials or failures, then explore exact, cumulative and interval probabilities with graphs and calculation steps.

Find the hypotenuse of a right triangle using two known sides, one side and an angle, or the triangle's area. Enter your values to get the missing length, a labeled triangle diagram, and a step-by-step solution.

Divide polynomials of different degrees with exact quotients, remainders, and a visual step-by-step long-division layout.

Divide a polynomial by a linear expression using an interactive coefficient table, with every multiply-and-add step explained.

Create a Venn diagram for two or three sets. Enter set totals and overlaps, or paste element lists, to calculate each region, unions, intersections and probabilities when the total is known.

Create and explore a bell curve using a mean and standard deviation or your own numerical data. Compare normal distributions, highlight probability regions, and see how the shape changes with the parameters.

Create an interactive probability tree diagram for sequential events. Edit branches and probabilities, calculate every possible outcome, and explore conditional probability, independent events, and sampling with or without replacement.

Look up standard normal probabilities, positive and negative z-scores, and common critical values.

Find Student's t critical values by degrees of freedom and one- or two-tailed significance level.

Find chi-square critical values by degrees of freedom and upper- or lower-tail probability.

Find F critical values using numerator and denominator degrees of freedom.

Compare an observed correlation with a critical absolute r value for a chosen sample size.

Explore an interactive binomial distribution table for exact and cumulative probabilities. Choose n and p, highlight values, and follow worked examples.

Use an interactive Poisson distribution table for exact and cumulative probabilities. Select lambda and event count, highlight values, and see examples.

Find common derivatives in a searchable table with power, trig, logarithmic, exponential, and inverse function formulas, rules, and examples.

Browse a searchable table of integrals with standard antiderivatives, trig and exponential formulas, conditions, and step-by-step examples.

Search continuous-time pairs, inverse transforms and properties in angular frequency or Hz.

Find unilateral pairs, inverse transforms, initial-value properties and convergence conditions.

Find discrete-time transform pairs, inverse sequences, properties and regions of convergence—not standard normal probabilities.