Free statistics tools
Calculators and choosers that run in your browser, show their method and are checked against reference software.
Plan an experiment
Sample size, power and sensitivity.
Choose a method
Test choosers and table analysers.
- Start here · Choose a methodStatistical test chooser: which test fits your experimentAnswer a few questions about your design and data and get the test to run, why it fits, what to do next, and R and Python code that runs as shown. Each rule is cited.
- Calculate2 × 2 table calculator: chi-square, Fisher, Boschloo, risk difference and odds ratioEnter events and totals for two groups. Get the expected counts, the test your plan chose, and the risk difference, relative risk and odds ratio with confidence intervals, checked against R and SciPy.
Effect sizes and intervals
Effect sizes, conversions and confidence intervals.
Check and report results
Consistency checks, corrections and reporting sentences.