Statistics calculators for every formula
Calculators for probability, distributions, hypothesis testing, regression, and data summaries. Each one is built to show the method behind the answer.
Popular topics
- DistributionsNormal Distribution CalculatorAvailable
- Variance & DispersionStandard Deviation CalculatorComing soon
- Hypothesis Testingp-value CalculatorComing soon
- Hypothesis Testingt-test CalculatorComing soon
- Hypothesis TestingConfidence Interval CalculatorComing soon
- RegressionLinear Regression CalculatorComing soon
- Hypothesis TestingZ-score CalculatorComing soon
- DistributionsBinomial Distribution CalculatorComing soon
- Central Tendency & SummaryMean Median Mode CalculatorComing soon
- ProbabilityProbability CalculatorComing soon
- Hypothesis TestingChi-Square CalculatorComing soon
- Correlation & DiversityCorrelation Coefficient CalculatorComing soon
Browse by category
Probability
Work out the likelihood of events, combine probabilities, and update beliefs with new evidence.
13 calculatorsParadoxes & Puzzles
Explore famous probability problems where the correct answer contradicts first intuition.
8 calculatorsDice, Coin & Combinatorics
Count arrangements and selections, and work out the chances in games of chance.
14 calculatorsClassification & Evaluation
Measure how well a test or classifier separates true cases from false ones.
5 calculatorsDistributions
Calculate probabilities, quantiles, and summary values for common probability distributions.
21 calculatorsCharts & Visualization
Turn a list of values into a chart and the summary numbers behind it.
11 calculatorsCentral Tendency & Summary
Summarise a data set with averages, quartiles, percentiles, and outlier checks.
16 calculatorsVariance & Dispersion
Measure how spread out data are and how precise an estimate is.
26 calculatorsCorrelation & Diversity
Quantify how two variables move together, and how varied a group is.
8 calculatorsRegression
Fit a line or curve to data and measure how well it explains the outcome.
8 calculatorsHypothesis Testing
Test claims about data, and estimate values with confidence intervals and margins of error.
22 calculators
Why use SahajTools
Show the method
Every calculator is meant to state its formula and assumptions, so you can check the working and not just copy a number.
Organised by question
Categories follow how statistics is taught and used: describe data, model probability, test a claim, fit a line.
Free and fast
No sign-up. Pages are lightweight and calculations run in your browser, so the values you enter stay on your device.
Clear limits
Results are for learning and information. Where a decision matters, we say when to consult a qualified statistician.
Where to start
If you are summarising a data set, begin with central tendency and data summary, then look at variance and dispersion to see how spread out the values are.
If you are testing whether a result could be due to chance, the hypothesis testing tools cover p-values, critical values, and confidence intervals. For questions about likelihood, start with probability or one of the distribution calculators.
Not sure which to use? Read our guides or contact us.
Find the calculator you need
Search by name, symbol, or topic, or browse the full list.