free
Tools
Free, no account, runs in your browser. With an explanation for every result.
Statistics
- Sample size calculatorHow many people do you need to survey?
- Power analysisSample size for t-test, correlation, chi-square
- Significance calculatort-test, Mann-Whitney, correlation, chi-square with a results sentence
- Cronbach’s alpha & effect sizesIs your scale reliable? How large is the effect?
- Descriptive statisticsMean, median, spread — and a chart
